How do I unlock my interior? I started working on the Starbase projects and found that for 1000 xp I can unlock the interior, I know I am asking a dumb question or is there a place I can read on this stuff?
You mean the 'inside' of the starbase? This should already by unlocked for you at Tier 0. Go to eti eridani sector. In the bottom left corner is a "federation starbase system". Enter the system. As soon as you get there, you should see your starbase. There should be a button on the right side that says "Dock". Click that and you will beam aboard your starbase.
Come join the 44th Fleet.