I built two Arcs on my first turn, sent them to separate planets so that I should have 3 planets next turn
I also built 2 Merchantmen and 2 Bulkfreighters and sent them to my nearest trading neighbour.
Turn 2, I found out that the goods freighters take are not taken away from your current total on the turn you build them and cried at needing 5 steel to get a 3rd colony ship. So turn 2 I started building Long Range Sensors and Slingshot.
Turn 3 I shall have enough for 1 Colony ship and I'm hoping at some point my steel production will go over 9k so I can get 2 colony ships on one turn some time in the future.
I want to get these planets nearest to me colonised quickly and get them producing resources. Then I'll think about a defensive fleet - or possibly a pirating fleet.