Since your a Terran you have 2 choices of either going commercial or agriculture. Once you choose which ever you want to be (food or creds) then you go to research at the top where the tree is put 6 into housing, then the research up to 15 for either commercial or agriculture NOT both Only one. Once you have chosen there is no going back really except restarting :( After you have done all that build some scouts and explore for some planets. try keeping 600+ at first if you can. go to manage colonies then click on the planet, put some housing on it first then the labor will rise once it does put some NOT all on either agri or commercial (which ever you chose up top) :)
That should help you make more money, if you have any questions you can intel me and I can explain more in-depth in the pm.