You seem pretty knowledgable (your sig), can't see why you can't figure this out, but here:
Run the VC-MP installer (like anything else, just run and install it), and when it asks where to point it too you'll most likely want it at C:/Program Files/Rockstar Games/Grand Theft Auto Vice City/ (or whatever your folder is). Your IP/Port (for a server?) would go to the command prompt (start > run > cmd) and type ipconfig/all, you'll see that stuff there.