What school supplies should I get for my junior year of high school?

You won't need anything out of the ordinary. Just get what you have been getting for the past few years of schooling! Also, your teachers may state that they want you to have this and that for their classes in the first week or so.

My personal recommendations are a maximum of 4 or 5 one-inch binders, a bunch of pencils, black, blue, and red pens, and a few highlighters. Don't get notebooks, as they suck. Get loose leaf paper instead. It's easier to stay organized with many papers because the number of papers force you to stay organized! You can toss a notebook in any old place but you need to sort through your papers. I think it's easier. The reason I say only 5 binders is that carrying a lot of them sucks. Put two subjects in each binder and that will help you stay organized too. Take out old papers that you won't need and throw them out. Keep the papers that you will need to study for long-off exams in a safe place.

Also, get a graphing calculator for your math and physics classes, if you don't have one already. It will be very helpful. Get an AP prep book for APUSH as well.

Good luck!