If you're not an experienced cyclist, I would do my best to talk you out of getting a fixie. A single speed is fine for short flat trips but I gotta say, most bikes out there have gears for good reasons.

Those reasons are:

Hills
Headwinds
Tailwinds
Good Days
Bad Days
Distances
Loads

If you find that you really like cycling, a fixie/single speed can be very limiting. Most of the people that I know with fixie/SS bikes, it's another arrow in their quiver, and not their go to bike.

As for riding to and from and around a university, cheap and inconspicuous will be your two most useful words. Anything expensive and/or novel will get stolen. Doesn't matter what kind of lock you buy,
if someone wants it, they will have it. Honestly, a $200 POS will be your best bet and yours for as long as you want to keep it. (POS stands for "Piece of Excrement"... only spelled differently)