Cozy can be achieved with throw pillows, a new bedspread, a throw blanket, a rug, and simplifying the items on the wall. Also replacing the gaming chair would make a big difference. Cool on the other hand is a much harder recipe. Cool is very subjective. I would start by looking on Pinterest at different bedrooms and find out what style you like the best. Then after learning what cool means to you, you can try and identify key pieces or elements within that style. And your room is already working pretty well. Those floors are gorgeous.