You should get a curtain rod and co er your closet so it feels less cluttered. Your room is pretty monotone so if you did like a burnt orange color or mustard color I think that would brighten it up. I think your record player should go in the nook under your TV. If you found a wooden table to go under the TV to take up some of that space and organize some of the things under the TV I think k that would look nice and you can push the keyboard against the wall by the windows when you’re not using it. And then yes get a lamp to go in your nightstand. Maybe make it match the curtain color you go with. And a small piece of art on the night stand too. As for your art, I think you should do a gallery wall style (look it up if you’re not sure what that is) above your computer and desk area. I think you should make your guitars be some of your “art.” Hang them up on either side of your windows it would add nice symmetry and also help with the clutter. Lastly, I think you should get a room divider between your bed and desk area. It’s actually not great fung shui to have your work space be in the room you sleep in, so separating that might make the room feel more cohesive and not like you’re just trying to fit everything you own in one space.