Housing - dorms vs. apartments

Hey guys!

I’m from Australia and will be going on exchange to the University of Arizona in Spring 2016, I’m currently trying to decide on housing and unsure whether to apply off-campus or on-campus? I’m 20 (will turn 21 in April) and want to meet lots of new people/have the classic American experience, but unsure whether I’ll be much older than everyone if I stay on campus.