you don't HAVE to have a 3 button mouse..but it will make your life a lot easier..and i just like the overall "flow" with the 3 button mouse...if you only have a 2 button mouse..you can assign new keys to do the camera movements that you normally do with a 3 button mouse...
go to window....setting/prefs...hotkeys...under categories...select navigation..and create your new command to whatever you like