I just purchased a 10 gallon tank, with filter, heater, gravel, real plant, decorations, hood with LEDs, nets, and plan on buying a gravel vacuum tomorrow. What other supplies do I need?
You should read up on the fishless cycle to save yourself some heartache. You'll need a source of ammonia and a test kit.
If you have a friend with a tank you can beg for some established filter media (sponge, ceramics, bioballs etc) to get your bacteria colonies started. It's not necessary but speeds things up for you.
Apart from that, and once your cycle is complete, you'll need fish and food.