Honestly empty room is pretty easy. It’s the people that have a bunch of stuff that make people think “is this a serial killer or are they just weird?” thats hard. You can tell they really like their stuff and you have to convince them to tone it down for new people.
When my room has been this empty it’s usually because I just moved and couldn’t afford to move much or had to sell a bunch to afford the move. Just ask the people you’re close to (ones you’re leaving, ones you’ll stay in contact with, and new people you meet) if they can make you some type of art to make your room feel more inviting. You already have a pride flag, seeing your friends terrible drawings, 4am and high quotes, etc is all you really need to add to make at least an inviting wall. Furniture is definitely nice and encouraged, but if youre living like this you need to be reminded you’re not really alone, not necessarily stuff at first. But please at least get a used side table at some point so you’re not spilling food in bed lol, speaking from experience.
Sometimes its also been, I didnt plan on you guys doing that and I’ll have to come up with stuff on the fly so please reconsider but I dont want to tell you that. You’re doing it anyway? Well damn, improv time.