Student housing in the spring might be a little difficult since everybody's already been moved in there for a semester. I'm not really sure where'd they put you.
And you do have to pay for a parking permit. See UGA's parking services for more information.
University of Georgia: Parking Services
About the weed...I don't personally know too much about it so...
There's a good number of older/non-traditional students, but I wouldn't expect a whole lot.
Well, as a transfer, they shouldn't be even sticking you in dorms made for freshman (Russell, Creswell, and Brumby are the main ones). A safe bet is probably ECV (or EVC...same thing). I know O-House has single rooms as well as Reed. I would look into off campus housing though. Housing, food, and parking cost a lot and it might actually come out cheaper if you get an apartment.