I'd say a helluva comfy bed would be nice. You may not get that much time to sleep so when you do - max it! Get a Seally. Anything smaller than a queen is crap. Get some high thread count sheets. They're smooth.
Seriously, when I first got out on my own some years ago (I'm 28), I bought a whole bedroom suit and big washer and dryer to really maximize my quality of life.
I later picked up a nice Ashley living room suit during a Labor Day sale.
Seeing that you're living campus is the reason I recommended quality bedding, lol. That crap they usually provide on campus isn't fit for the homeless.