I always had a little unbreakable crucifix and a Mary statue. When I got my own room, I had a picture of the Sacred Heart on the wall over the bed. I kind of wince now realizing how much sin was happening in front of that picture, but at least the Lord was there.
Only be worried about your roommate if they’re the type who will steal, break or dishonor your stuff.
I also recommend you don’t take anything expensive, breakable or irreplaceable. Even if your roommate is a good person, stuff has a way of getting broken or lost in dorms. All it takes is one person coming over who isn’t careful in a small room. If you can lay hands on some plastic stuff like what churches give away, what you buy for a couple bucks at a Catholic store, or get for free in charity mailers sometimes, those are good choices. Leave the heirloom or special gift your grandmother gave you at home.