Don’t worry about the broom thing if this is a shared house, that’s really a “one per house” type of thing, no need for every tenant to have their own.
The desk/storage next to it is getting a little cluttered. Be careful of that, it’s a natural starting place for mess to creep out into the rest of the room.
You don’t feel like an adult because you’re 20. You barely are one, it’s okay. You’ll figure things out as you go.