What am i doing wrong?

hard to say only from the information you've given.  A fully mature Advent fleet should kick the teeth of an easy computer in.

What sort of fleet composition you using generally?

What capitalships do you prioritize?

Are you actually manually casting your capitalship abilities or are you leaving them on autocast?

Are you Issueing focusfire orders to your fleet and otherwise microing your frigates?

What sort of defenses are present on the planets you're attacking?

In general though if you're just starting to play sins,  might be a good idea to start on TEC rather then advent.  I'm a fanatical Advent player personally, but they aren't the best race to learn the game on(they are more heavily dependent on micro/synergy then the other races and their poor economy means there's not much of a margin of error in terms of choosing how to spend your income properly).  TEC is probably the best race to learnt he fundamentals of the game on.   That said it's not impossible- just expect a bit of a rockier road starting as the advent.

I was hoping the intel was enough:(

I start with a mothership to capture nearby planets.

A full fleet consited out of 4 of every frightet 1 of every capital ship(all level 4) no scouts and disiple vessels make up the remaining fleet points.(for there antimather control)

I useally target the capital ships first in hope's to kill it so the frigate's are easier to kill(probley what i am doing wrong)

To many ships to manual cast so i let them auto cast.

Planets are generaly easy to kill(little to non defendse) but once there fleet show up they have homefield advantage(culture wise) and there fleet is as big as mine.

Abilities:

hmm, well first off, letting capitalships autocast as a rule is a bad idea(the AI sucks for most abilities).  A few abilities are alright to autocast(perhaps Radiance Animosity, Rapture vertigo, and Halcyon Anima tempest are OK to autocast).

In general be wary of letting your ships autocast anything that will quickly run them out of AM.  Even vertigo which I listed as "ok" can run Raptures out of AM quick at lower levels.

A few abilities to watch out for:

Vengeance on the Rapture sounds like a cool ability, but right now it sucks and is largely a waste of AM(so don't waste points in it).  

Malice on the Progenitor is great when coupled with AoE damage, or extremely large amounts of weapons damage(if you have a colossal fleet), but most of the game if you lack AoE the AM would be better spent on Shield Regeneration.  As a result Malice should never be left on autocast as the AI isn't smart enough to only use malice with AoEs.  Also while malice may sound cool, it's generally the lowest priority skill on the progenitor to level up-Colonize is a huge boost to early game economy, and Regenerate shields is one of the single most important capitalship abilities the advent have.

As I'll touch on later the Radiance Battleship is a kind if weak capitalship, but if you do build it make sure to dump points in Detonate Antimatter first- it is by far the Radiance's best ability.

Fleet Composition:

In general it sounds like you may be overusing Discipels a bit.  Disciples are mostly only the body of your fleet early game.  Late game Disciples are only really meant to counter support frigates and carriers.  They get wrecked by heavy Cruisers and Long Range Frigates which are very common in late game fleets.

For fleet composition your main late game workhorses will generally be carriers loaded with bombers or Destra Crusaders rather then Disciples- these units should be where a bulk of your fleet's weapon damage comes from late game.

In particularly in the super late game carrier fleets are devastatingly powerful-together with the Rapture's Concentration Aura a fleet with maybe 50-60 squads of bombers is a mortal threat to any capitalship(and truly mature fleets with 80-100 squads can kill many capitalships from full in 2-3 bomber passes).  Building a huge carrier fleet is also pretty much a surefire way of beating the AI(it has no clue how to deal with mass bombers).

Disciples, Defense Vessels, Carriers loaded with fighters, and Illuminaters will more often be early game workhorses or built as counter-units.

Iconus Guardians are key to any late game advent fleet.  Grab 3-5 of them in a fleet.  You should really manually cast both their abilities(not so hard to keep up with as you basically just need to order a new shield projection every 30 seconds and situational Repulses).  Repulse also synergizes a great deal with Carrier Fleets, allowing you to keep enemies away from your carriers

Also don't bother with the Domina Subjugator at all if you don't want to manually cast it's abilities.  It's not really a "necessary ship to the advent's strategy in general due to how unwieldy it is at the moment.

Capital Ships:

Also I may as well touch on capital-ship composition: For the Advent both the Revelation Battlecruiser and the Radiance battleship are considered to be rather weak and generally are only built when the interrupts they provide are needed.  If you want raw firepower grab a Halcyon- all three of it's abilities are amazing and the extra squads of fighters mean it has way more firepower then the radiance.

The Rapture is primarily a late game ship- so your main early game ships are progenitor and Halcyon.

You only need one Rapture- but in super long games a second mothership is goo, and more Halcyons are always useful.  Radiance may be a niche counter-ship you build occasionally when he enemy has a particularly troublesome capital ships such as a high level marza or Dunov.  

Putting it all together:

The Advent is all about synergy and has more ways of mitigating damage then any other faction.  Between Iconus Guardian's shield projection(and eve in long fights you should ALWAYS make sure some guardian is projecting it's shields at all times), Vertigo on the Rapture, the advent's high shield mitigation, and the progenitor's shield regeneration enemy fleets will often find it difficult to put a dent in the advent fleet(except for the vasari- they cheat with their shield-ignoring phase missiles).

Meanwhile the advent fleet uses it's primary damage frigates coupled with their respective auras they benefit from to dish out a ton of damage(concentration Aura from the Rapture buffs carriers/bombers and Energy amp Aura from the Halcyon buffs Destra crusader damage output).

However between Auras, regenerate shields, and Guardian shield projections you generally want to keep your fleet in tight formation so that all your ships are close enough together to benefit from each ship's AoE effects.  This gives rise to the so called "battle-ball" formation Advent fleets tend to take.  This often means you want to have your fleet set to "hold position" and need to be careful to not let any of your ships chase enemies alone and fall out of formation.

Anyway that's all that immediately comes to mind on advent fleet tactics, hope some of it is useful.

That was very usefull indeed.

I thank you for the infomation.

Just one final question:

I play advant of the go because i am a sucker for psychic powers.

Not because  of there playstyle:

I would like to know the different playstyle's of the 3 factions(generaly speaking)

JUST TO ADD SOME MORE!! Now in rebellion, if u improve culture spread rate with the Advent in their research tree, u have a chance to block those cheaty phase missiles from the Vasari   (it is useful? i dont know! Vasari aren´t out yet!! T_T)

Glad to help.  in a nutshell it comes down to this:

The TEC are all about having a very strong economy.  They get their economy running faster and stronger then any other faction.  In long games they use Novalith cannons to ruin their opponenet's economy.  That said the TEC endgame fleet is weak- by design.  The TEC are supposed to fight a war of attrition and attack on multiple fronts to force the opponent to divide up their fleet(an end-game TEC fleet will lose a direct confrontation with an equally large endgame fleet from another race).  This is not to say the TEC never can directly attack- if they play a good early game and their economy is far enough ahead they may have a stronger fleet by simple virtue of having had a lot more money to spend on said fleet.  The particularly strong early economy also means the TEC is probably the best faction at putting early game pressure on opponents(especially with use of the Sova's embargo ability).  One noteworthy TEC unit is the Ogrov torpedo frigate, which is by far the best siege ship in the game- it can only attack buildings but does so from outside starbase attack range and does enormous damage to buildings.  This ship allows even small fleets to be a potent threat to enemy planets, allowing small attack fleets toe asily force the opponent to divide up their fleets to defend.  Also noteworthy is the Hoshico's Robotics cruiser which is easily the best early-mid game support ship in the game.

The Advent has a few strong points(they are a bit underpowered as a whole right now, but that should change when rebellion comes out in the next few months).  Advent has the best T0 ships per cost(scouts & light frigates) and while we're at it probably the best flak frigate.  This means in very small maps the advent have access to a very strong early rush strategy as before other races have time to start leveraging an economic advantage the advent has better ships per cost.  The advent's main schtick however is fleet synergy.  The advent mid-late is all about having individually weaker ships that through synergy create a stronger whole.  The result is the Advent end-game fleet is extremely strong(as by then pretty much every synergy has kicked in).  That said, the advent probably requires the most micro & knowledge of any of the races as it is necessary to know & make use of a large number of synergies and skills.  One of the most important skills for an advent player is learning how to be very frugal during the early-mid game as the advent has a weak economy and you need to avoided wasted expenditures, only spending money on what is really necessary.  It's also worth noting the advent probably have the edge in maintaining air-superiority with strikecraft.  While their bombers aren't as strong as the vasari they probably have the best fighters, have the best flak frigate, and Telekinetic push is the single best anti-strikecraft capitalship ability in the game.  Also a minor advantage i nthe current game is that the advent have the strongest culture- this is most notable in that they can upgrade their starbases to spread culture.  Probably the most noteworthy frigate in the advent arsenal is the Iconus guardian- it provides widescale fleet damage mitigation and Repulse is downright gamechanging.

The Vasari like the Advent are a primarily Late game Race.  Their Phase Missiles are hands-down the best weapon type in the game by a huge margin and they are fortunate enough to have both of their main frigate damage sources use phase missiles(Long range Frigates and bombers).  The chief advantage of phase missiles is they shred capitalships allowing the vasari to focusfire and kill enemy capital ships faster then any other faction.  The Vasari's biggest playstyle distinction is mobility- they are all about having very high mobility, having access to tools that allow their ships to jump accross the solar system rather then just to adjacent gravity wells.  It's also worth noting that the vasari have the only offensively specialized starbase(it can move around a gravity well, they get a technology that makes starbases build 50% faster in enemy gravity wells, the starabse has a weapon system which does bonus damage to other buildings, and to top it all off the vasari starbase is the strongest stand-alone combatant of any starbase with superior weapons system and survivability upgrades).   Militarily though one of the biggest Vasari advantages is their bombers.  Their bombers are harder to kill then most races bombers(doubly so being that their carrier has an ability that heals all nearby ships including strikecraft and carry phase missiles.  An early game rush strategies for the vasari invariably involves 1-2 carrier capitalships fielding bombers.

Anyway hope that helps- a bit rambling I know, just kept adding aspects of the factions as they came to mind.  I suppose the short version would essentially be:

TEC: Strong economy

Advent: Synergies between ships

Vasari: High mobility and strong focus-fire potential

Thanks for the detailed explantion.

After reading that i now know why i suck at advant it is exactly how i hate playing:P

So either tec or vasari.....

hm vasari high moblity and focus fire means there exellent for kill enemy without ever meeting there fleet.

Sun-tzu art of warfair: attack weakness avoid strenght.

Then again tec having a near endless supply of income is also very usefull.

A dull blade isnt effective after all.

Could you give me more detial on tec and vasari(in terms of how they differ in playstyle)

Nice list man