I loved my Dremel when it came to foam modeling but make sure to wear your mask and safety glasses because it kicks up a ton of dust, much more so than manual sanding. If you have access to power outlets at your workstation I would go for a corded Dremel over a cordless, that way you won’t have to wait for batteries to charge. Otherwise I’d suggest getting a second battery to have on hand.
Clamps of various sizes are incredibly handy. I have a set of some tiny QuikGrip clamps that I used all the time and a set of bigger ones for 1:1 scale furniture projects and stuff. There’s nothing more frustrating than going to glue two pieces of a model together then realizing you have no way of holding them together while the glue sets besides sitting there holding them together yourself.
No matter what you put in your toolbox, label EVERYTHING permanently with your name or some other distinguishing mark. My first Dremel got stolen in studio and I never got it back despite telling all the faculty and students to keep an eye out for it and searching my studio space, apartment and car for days. For other, smaller things like hand tools all your classmates will have very similar ones and unless you have yours marked they’ll likely get mixed up with everyone else’s.