Well, if you just downloaded it, there's a chance that the install itself is messed up, so if nothing else works you can always uninstall and reinstall. Do a search for "Adobe clean script" before you uninstall.
But, assuming that your install of ID is not borked:
1) Just whack the tab key. (That hides most of the UI. It shouldn't start hidden, but it's the easiest thing to try.)
2) Up in the upper right hand corner of the screen, there should be a workspace selector. By default, I think you'd start with the "Essentials" workspace. Can you pull that down and choose a new workspace? Does that change anything?
3) And, of course, you can always go to Window and open a panel. Does that work?
I have no idea what's going on on your side, but I think if you try those things and report back then we should have a little bit more to work with.