Sort all paperwork out by categories making small piles of each.

First do a rough sort: keep, trash, donate, put somewhere else. Next, take out the trash, move the "put somewhere else" aside for now. Ask a parent to help you donate items that you have outgrown. What's left are the keepers. Put the things you use the most in the easy-to-reach spots, and the once-in-awhile in the harder to reach spots (back of the drawer, a top shelf). Last, decide where the "put somewhere else" items belong. If you need to organize that space too, that's OK. Just don't try to do it all on one day. You can do it!