You can take classes on both simultaneously, I currently do. In terms of a car, it's always easier with a car but UB is pretty good about the bussing and is relatively close to things. For example, every weekend there are busses to the local grocery stores and the mall, as well as frequent busses between campuses. South campus is located right next to down town so u basically walk a few steps off campus and u can walk into a club or frat house. North campus is located less than a mile away from the local mall/ many restaurants. That being said, it gets pretty cold here and can snow a bunch so walking anywhere during the winter is a chore if u have to. That all being said, people get along just fine without a car, but it always helps to have one if u can.