Its really best to dive right into a sandbox game i think. I don't know what your experience is with other TBS games so i can't tell you what level to start with. You may have good understanding of what you need to do from reading the forums like you said you did; now its just learning HOW to do those things.

Learning the game should be fun even if you don't do well at first. Seeing things happen for the first time can be exciting.

So jump in and if / when you hit a snag post a question here and you will get all the answers you could want.

Have fun

I'm glad I found this thread! I had problems learning how to play this last year but I bought the Ultima Version today and i'm giving it another shot!

Okay, first, learn the basics.

Watch the tutorial videos. Personally I'd prefer text, and rather would just ignore the damned video enteriely but Cest La Vie...

regardless once you've got the basics down start up a tiny game. Play with a customized race. I like to use My confederation of Augments, Terran based tech tree with super adapter super ability.

once you've played a tiny game move onto a small one. Then a medium and so fourth.

I started an immense game and It's gonna take me WEEKS.

Coming from SEIV you shouldn't have much of a problem.  You can't mothball ships but you can upgrade them in deep space.  Overall it is a less complex game with a softer economy- you can always sell influence points at lower difficulties to make up any shortfalls.