If it's an unsecured wi-fi, you have already made available to other users your password for Email & Facebook - and if you've done any banking or other similar transactions, your bank login as well.
Having said that, wifi is an internet connection, so you can do whatever you want that you could normally do on an internet connection, although some functionality such as peer-to-peer file sharing, gaming, etc may be blocked by the router. If it is not truly public wifi and you're just using someone's unsecured connection, in some jurisdictions you care performing a criminal act.
Well, since it's the University you go to, make sure you read their WiFi/Internet usage policy to see what if anything is not allowed. Otherwise, it's whatever isn't blocked by the University hardware.