The most common drug on campus is weed. UPD takes drug use pretty seriously, and if you are caught, expect to be suspended from school, or in some cases, expelled. Weed is pretty prevalent, and if you ask around, you will be sure to find someone who knows someone who could get it for you. As far as other drugs on campus, mushrooms and ecstasy are also used.
Because of the University's love affair with high techno/dubstep music, UF tends to get concert acts of this nature, and a lot of people think it's normal to do ecstasy at these concerts for the "rave effect."