so if it's not wise to bring a car, and the subway is not exactly safe, how are we supposed to get around?
lol, how is your name nycNerd if you don't know anything about the subway.
It's perfectly safe so long as you don't wait until there's only one other person on the train car with you, and then you start waiving around a diamond encrusted ipod or something ridiculous.
I've ridden the train for years, from Harlem back to Queens at 1-2AM, from Brooklyn back to Queens at 3AM, whatever. And from Queens to Chinatown like every dang day at every possible hour.
And guess what, still haven't been mugged or even pickpocketed yet. In fact, the only time I've ever been pickpocketed was by a hot dog stand, when I was in high school and kept my cash in my wallet (don't do this btw, it'll just get your wallet jacked, use a money clip instead).
Now, if you're a somewhat attractive female, you might need to be wary that there are going to be exhibitionists who will run up to you or sit across from you and then try to show you their genitalia. This has actually happened to more than half of my female friends in NYC, so I'd presume that it happens an awful lot. Nothing actually happened to them physically btw, these perverts just run off at the next stop usually, but it's still quite disturbing. Plus I think one of them did it to my friend's like 16 year old little sister.
But hey, you'll be a med student so you'll know perfectly well what all those body parts look like anyway

I'm pretty sure they just do it to see the look of shock anyway, so I'd just start laughing-probably ruin their self esteem.
If you're a guy, you don't even really have to worry about sex perverts.
And of course, if there aren't that many people around, try to stick to a conductor car and you'll probably even avoid the perverts.