Darkke

I fianlly got the game and, of course, jumped right in. I have read many of the post here and I still cant seem to do a darn thing in game. I get good planets, (I think) and try to get tax $$ coming in. I seem to always get ganked and have no real way to defend myself. Also, should I be putting one of each building on a planet or set certain planets to do only certain things? One last thing, how the heck do I upgrade my ships? I click on upgrade, and Im lost Sorry if this