I don't think there's a big deal about going first. I didn't get asked any crazy questions, just a few things about Liechtenstien (but I mentioned I visited there, so it wasn't an out of left field question) and I had to answer why I never did any research in college. Plus, you get it over with, and then you don't need to worry about your hair frizzing and you can just relax and enjoy the rest of the day (if you ahve a morning interview.)
Don't expect an indepth fin. aid presentation. At my interview, the guy came in, passed around a few papers, pointed out the tuition, and then said they'll talk about it more after you're accepted. Ok, fine. You get lunch, the mayo and mustard is hidden underneath the potato chips, and don't be afraid to open the cookies. After lunch is a tour of the school. They'll show you the anatomy labs, OMM lab, the library, maybe the DPC suite, the clinical practicum area with STAN, which is really cool. Apparently, the woman is able to make STAN talk by talking for him, she can make him blink, all this stuff. That's actually really neat.
Longest part of the day is waiting for your interview. But we were all joshing around when we were waiting for our interviews. A few random people stopped by to talk to us. And parking is absolutely not a problem, just make sure you go to the osteopathic college adn not the first parking lot you see. Just follow the signs.