Find ports question, please help


Solid State Member
I'm in college inside a dorm room and I need help trying to get my firewall lifted so I can game online with my PS3. First thing I have to know is how do you find out what ports you need? Second, it asks for a Protocol (TCP, UDP), Outgoing/Incoming, and Service (http, ftp, telnet, etc)? I thing protocol is my IP address but no clue what everything else is. Last, it asks for a outside Ip address, i didn't know the world has one and if so, where? Can somebody please help, thanks.