Such a good game.
My first advice is at least get the expansion with the random goals. It can give you more direction at the start of the game. (for example going Alien or Uplift is a high risk strategy that often doesn't pay off but the goal cards can make it worthwhile)
Next tip is never rely on waiting for one or two cards to fall in your lap. Even if you have insane explore bonuses and searching through 10+ cards a turn, each time you do you're probably falling further and further behind in tempo. Be flexible and play the cards you get, don't just wait for the cards you want.
Lastly RftG is not a game you can win every time. Sometimes you just get unlucky or someone else draws the nuts. In that case fight for 2nd or 3rd, be happy if you succeed and make sure you tell a cool story with your cards.