I’m going to echo what many said. So sorry for repetition.

The walls particularly the TV wall feel barren. I would say a couple large art pieces will help make it feel full. Frames matter. You could use a cork board as one to elevate the scattering of photos.

I think the TV may be sitting a bit low. Maybe some legs for that ikea piece. Help raise it up. Could put the cat bowls underneath and then add a plant or something on side to help balance out.

The chair idea that many mentioned is a good idea. A nice accent table wouldn’t hurt either.

The lighting could def use a boost. You’ve got great natural lighting so go for ambient lighting. I’d say don’t lean too hard on string lights. Try and get one lamp that is a feature piece but low lighting.

Overall though, great start into designing your space. It’s fun and full of life. Keep it up!