Staying organized is important, because it keeps your life on track and clutter-free. The three areas you should work on keeping organized are your school bag, your room at home, and your locker.
When it comes to your school bag, maybe you want to get different binders that color code and match up to different notebooks for each class. That way, in the morning, you only have to pack what you need, and you don't end up carrying around a bunch of extra clutter.
For your room at home, it's incredibly important that you have a space to study. If you can't fit a desk, get a lap desk. Just make sure that whatever area you're focusing on, is distraction-free.
When it comes to your locker, you want to get a locker shelf and a pencil holder, so that you're always super prepared for class and you have a place to keep your books.
When it comes to organizing, you need to remember three things: sort, purge, organize. That means put everything in the categories, get rid of the stuff you don't need, and find a place to keep the rest of it. If you find yourself having too much clutter, that means you need to go back and do the steps again. For me, the problem is always getting rid of stuff. I'm always thinking, like, "Oh, I'm totally gonna need this. I'm definitely gonna need this." and then, guess what? It sits in a box, and I never use it, and I don't need it.