Where does one get the forms for an event? Also what exactly is an entertainment contract used for?

You can find them under the Forms menu on this site as a pdf file. You can print them up from there (either with typing in them, or do it by hand). Otherwise you can go to the Student Association Business Office (SUB 428) and get them from across the hall.

An entertainment contract is generally used for getting someone to come on campus and perform something (like say a magician).