I honestly think most questions asked here are covered in the step by step tutorial on the wiki, including ship design, task group organization, etc.
I used that when I started.
To the other discussion, in my current 5.02 game, one jump from Sol, I discovered an Alien race with just one planet, that either has a population of around 50 million top, or no real industry.
During the last 10 years, they didn't build a single space ship, nor did their emissions rise by any noticeable amount.
they are obviously either a bug (I had a one billion start), with extremely low pop, or pre-TN.