First step would be to clear out EVERYTHING you dont need, just throw it out or give it away- you will feel great! give the room a good cleaning and try to organize as much as you can. Paint the walls a fresh color and sand down and repaint the bunk bed. I dont know where to get slipcovers but get a solid color and fun pillows. if you have the space get a small lucite table to stand the TV on. Really though it seems from your pix that whats most impt right now is a good thorough cleaning and organization job.