Space games, particularly the real time ones, do tend to have a really big learning curve. There is worse than Sins out there, beleive me ! 
X3 for example is incredably difficult to learn how to play, and literally has dozens of guides written on how to play it without going mad. Sins by comparison is actually quite simplistic !
The best way to learn is play. Expect to get killed in the first few games, and just ask questions about why. Why can they build so many ships when I never have any money myself ? Why do pirates keep attacking me ? etc. Each question leads to finding a new feature of the game.
Most aspects of the game have something obvious, something somewhat hidden, and ways of improving things. eg. Money - planets are colonised generally account for how much money you have by its population and they cost you money until you upgrade them so they dont have a negative tax amount. (find that quick). Thats the hidden part. You research more population, both on the planet and in the research screens. Then researching and building trade stations improves your money. The timing of all this depends on your strategy and what else is happening. If you are in big battle with an enemy AI from day 1, then your just not going to have the resources for extensive research immediately as you will be madly building ships. So a bigger map, less phase lanes, less enemies, gives you time to figure things out.
Learning what order to do things is just part of playing games and getting your arse kicked different ways, and reading the forum for similar questions you have and their answers. If you cant find it, ask it. You always attract some negtive responses because the world is full of negative people who just want to put you down, but ignore them, there is plenty of us who are here to help and will.
I suggest a number of games with easy AI's, set them to everything except aggressive, turn off the pirates, lock the groups, use a map with short and few phase lanes. Select a large map, with only a few AI's. This gives you time to build a small empire before your forced to do more than minor battles, lets you do some research so you can see how some of the advanced features help you, and gives you breathing room for a while. Sure, its likely someone will stomp on you sooner or later, but figuring out why they could do so is part of learning the game and we all had to do this.
When you win a game on easy, set the AI's to normal, then move up to hard. By that time you should have the hang of the game and are ready to unlock the teams and allow pirates and experince how that changes the game and make decisions about how you to prefer to play the game.
The main thing is to accept that the game has a learning curve, and play it initially on the expectation of getting your arse kicked and learning why it happens and figuring out how to do better next time.
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