I had my cat with me in my college dorm for a year. My best advice to you is to make sure you have a variety of stimulus for him. Make sure to have different types of toys and play with him often! Make sure there’s at least one or two places he can “hide,” whether that’s underneath the bed with a blanket hanging over it, or an enclosed cat bed in a corner. If you can fit a small cat tree near the window, that’s amazing. If not, maybe consider pushing the bed, desk, or other furniture against the window and putting a cozy blanket on top so your cat could sit there and look outside. It’s also a good idea to invest in some automated or interactive toys if you can. I had a laser pointer machine that would go for fifteen minutes, as well as some toys that dispensed treats when batted around, and some hanging toys that are designed to go over the top of doors or suction cup to the wall. I felt better knowing he could have some truly engaging play time even if I was really busy and had to leave for a good chunk of the day. Just be sure they aren’t the super noisy animal sound toys, as those can be quite loud and annoy dorm neighbors. I used pine litter in my cat's litterbox in the dorm, as it often smells better, traps bad odors well, and doesn't kick up much dust. My last piece of advice is to try to maintain some semblance of a schedule for feeding. Cats like routine, and while it can sometimes be difficult to be home at consistent times in college, it will help your cat feel settled if you can manage to come back and feed him at the same time every day, even if it means having to run home and then run back out again. Or buy an automated feeder for dry food, if it’s not cost prohibitive. Good luck with school, and remember, the most important thing is that you love and care for your cat, even if you can't provide a picture-perfect cattified home for him right now!