overwhelmed in 10 minutes!

No, that's just Sins learning curve. Granted if you were playing on the default settings it maybe a little slower, but with Quickstart on and fast or faster build speeds I can usually colonize at least 3 planets in the first 10 minutes and certainly build a fleet that large no problem (and I am at best a decent player). You just need practice so you can expand faster.

If you're fresh from the tutorials I would try a game by yourself with no AI. The tutorials teach you the basic mechanics but don't do anything to help you figure out what all the research and ships do. If you have trinity/expansions that's even more content you just have to figure out by yourself. Playing without the AI lets you practice at your leisure, allowing you to build and research at your own pace while getting a bit practice at managing an empire and expanding and capturing neutral planets. If you leave the pirates on you can get a bit of combat experience as well (they only attack one planet at a time), but FYI the first pirate raid has around 20 ships, so make sure you have a fleet that large as well by the time they come around.

Another thing I would try is a different map. Those first few nonrandom maps are extremely small with your homeworlds right next to each other (thus rushing in extremely easy). Most games aren't like that, on the random maps you usually have 3-5 planets between two players, giving you more time to expand before fighting serious enemy forces. If you want to play without an AI opponent I would try a random medium map. For your first 1v1 game against the AI I would try random small or Gaian Crescent.

Make sure you build a capital ship early; your first is free.  The funds you spent on planet development might better have been spent on expansion.

I suspect you chose "Point Blank" as your starting map.  This scenario has both players starting side-by-side, so combat begins literally immediately.  Normally on this map you'd expect to be attacked within 1-2 minutes, but since you set it to easy I could see the AI waiting 10 minutes before it invaded.

Make sure, as Morthion has mentioned, to build your capital ship immediately.  You also want to explore to discover the layout of the solar system.  Find planets with weak militia that are easy to conquer and head out there to capture them.  Asteroids are particularly nice since the militia is so weak a small force of frigates can beat them.

For military, try to unlock stronger units as soon as possible.  Your starter combat unit is actually really weak, and not much stronger than the scout (in fact, against many types of enemies, the scout is actually superior to the light frigate).  Try to unlock the "long-range" type unit for your faction.  For Vasari, that's the Kanrak Assailant (1-lab), for the TEC that's the Javelis LRM (2-lab), and for Advent that's the Illuminator Vessel (3-lab).  If the enemy is in close proximity, your expenditures should be pure military; build the labs, research these unit types, and build as many as possible.

Defensively, your best option is the repair platform.  It's great for keeping units alive in battle, and if you retreat injured units they can be brought back to full fighting strength very quickly.  If you're going to invest in defenses, this is the one you want.  Still, avoid over-expending here.  A strong fighting fleet is always your best defense.

Unless you're playing on Point Blank or something, the AI, especially the Easy AI, should take much longer than 10 minutes to get to you. The AI usually takes like 5 to 10 minutes per (neutral) planet it takes. So you really should have a decent amount of time to get started before you have to fight the enemy, if you're playing a 1v1.

In larger games (like Random Large or Random Huge) , there are fewer planets per player to go around, but the galaxy radius doesn't increase that much as well, meaning that there's much less time to prepare. If that's the kind of thing you've been doing I highly recommend starting out attempting 1v1 games instead, on "Random Small" maps.

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If you're having trouble killing the Easy AI, try this. Play as TEC in a 1v1 random small against an Easy Researcher AI, with Pirates off and Quick Start on. Queue an Akkan as your free capital ship, build 2 military labs, research LRM frigates, and set your homeworld's Rally Point onto your Akkan capital ship.

Queue as many LRM frigates as you can. Once you've built as many as your supply can hold, go up a supply level and build more. Repeat.

Your scouts should have scouted a good amount of the galaxy by now. Once it's built, send your Akkan towards the enemy, colonizing planets as you go. Your LRM frigates will be supporting your cap. (Remember to develop Civilian Infrastructure on your newly colonized planets ASAP, or you will lose a lot of credits to underdevelopment) Once you start running into your enemy, you should have 30-70 LRM frigates along with your Akkan. They will completely decimate whatever fleet the AI has and you should be able to steamroll their homeworld in well under an hour, even with no micromanagement at all.

For learning the game, try relying on a fleet, not on static defenses. Don't build turrets except as a last resort.

Small combat ships take 15-25 seconds to build. Even were the AI to attack you 10 minutes in (which it shouldn't), you should be able to have a good number of ships yourself by then.

Also: If you haven't already, TURN PIRATES OFF. They're very difficult for new players to deal with and impede learning of the game.

Oh Rick, -dear old Rick i think the first thing to overcome is " how can i not get my self overwhelmed."

Which means you have to balance the books Rick or Over budget in this case. If the enemy brings in 15 ships then you should have 30 ships waiting for them. That's what i mean by-over-budget. Are we on the same page Rick?

So how do you overbudget:

After you research the planetary under-development option for a bigger population on your planet and have built all the resource mines on the gravity well's asteroids then sit back and build your capital ship factory with the free capital ship and just build units for 10 minutes. Build as many frigates as you can. Build 50 even. whenever you get money just que up some more units  because the more you do that then the safer you will feel 10 minutes later.

So step 1: Build as many units

Now that we can get past that part im sure the rest we can work out later.

Rick you can't balance the books or over-budget if its one  missile platform. That is a very low number compared to 15 ships and there just stationary defenses that are vulnerable and can't retreat. Missile platforms  won't help you even if you built dozens  because you can't use them to colonize other worlds while ships can. Balancing means if the enemy as ships then you need ships-not defense structures. Are you with me Rick?