When I have more time I'll swing back in and comment on housing, some employment stuff, and cars. For now, if you live in the Jeffersonian or anywhere on Arlington a car is not necessary at all. If you live in Ivy, it's kind of far to the grocery store but still doable without a car. In regards to housing it's not even on the radar yet, don't worry.
Agreed -- it's really much too early to be worrying about housing as of yet. Jeffersonian needs to be considered for its January 1 waitlist, but you have a few more months for that. You can put your name down for a 2 BR by yoursel, I think, and find a roommate later. Trust me, you won't have any problem finding one, because the vast majority of incoming 1Ls will have gotten in after January 1.
Re: cars. Joeshmo is correct again. Jeffersonian/Arlington makes a car unnecessary. Ivy it's somewhat more difficult, but still possible. The University bus system makes it a lot easier. From the front door of Harris Teeter to the bus stop (directly in front of Buffalo Wild Wings) is about a 1 minute walk. The bus departs from there every 10 minutes, on the 10 minute mark (i.e. leaves at 4:00 pm, 4:10, 4:20, 4:30, 4:40, 4:50, 5pm) on weekdays, every 20 minutes on weekends. It's free, and you don't even have to show your ID.
If you get off at Faulkner Housing, it's just to the side of Ivy Gardens, and you can walk right up. Depending on where you live in Ivy, it'll be roughly a 5 minute walk, which isn't bad at all -- just about the same as living in Jeffersonian, if you live in an Ivy apt. closest to the law school (highly recommended).