How should i decorate my room?

The best way, I feel, to decorate a room is to start basic. You said that your favorite color is blue/purple. The first thing I would advise is to be careful if you were thinking of painting your walls those colors. I made that mistake once and it just made the room feel so small and dark because my walls were so dark. Maybe you could consider painting them a light blue with one wall a darker shade? You could always add the colors through your bedspread, curtains, or a throw rug. Personally, I like to just paint my walls white, because you could always cover them with pictures (of friends, you, your childhood), posters, maybe some team portraits. Basically, what I’m saying is to not go with a theme, but instead, choose a color scheme and personalize it with things that mean something to you.
As for other things to put in your room, I actually like walmart’s new line for dorms. It has a lot of things for storage, seating, desks, and other decorations. And everything comes in a wide variety of colors. If your not digging that, just search aroung Target, Ikea, or any other department stores that I can’t think of right now.
Good luck with your room!

a cool thing to do is to frame posters if you have trophies put them on a shelf

paint the room kinda sky blue and put some posters of sports, football teams, rock bands, and maybe some posters of bikini clad girls to make it look real good

PIMP IT UP A BIT!