This is just a quick edit, nothing great. I just brightened your background, put a bit of a white vignette around it and sharpened etc. If i had the original pic at original size...i could have done more, but editing small pics tends to make them look grainy etc. As for brightening up the background...i can tell you how i usually do it. I sometimes tend to suck at explaining lol, but i will try.
1.I use my magic wand tool and select my subject. (if the subject has the same colors in it anywhere, as are used in the background...this might select part of your subject too, in this case make a duplicate copy) (will explain in a sec)
2. After selecting your subject, feather your selection. I usually feather mine about 11, but it will depend on the size of your picture.
3. After feathering, go into your levels and slide it until it is as bright white as you want it. this will brighten up your whole background, and take away any wrinkles it may have.
4. Ok...now for why you made a duplicate. IF your selection tool has grabbed part of your subject...then just copy paste your new brightened layer on top of the original. Then lower the opacity so you can see the original underneath enough, and erase the part of your subject back in that was colored over.
I hope i explained this ok. Sorry if i didnt. Just let me know if you need any help.