Hi!
I built a star base on earth
Ummm, what game you're asking for? It couln'r be GC, because in it no SB can be build over a planet.
If it is GC-2, then you need to click the rightmost button on the lower edge or the game screen to get to the shipyard. For further info check wiki:
Gameplay: Constructing ships.
BR, Iztok
