How does tax in japan actually work?

Hi. Japanese teenager here. I want to start a little buisness while I'm a student so I can save up for college (since I want to go to colleges abroad not in Japan and those things are EXPENSIVE in the U.S.A). But I don't really understand if I can even start buisness on my own, and I definetly don't know anything about tax when it comes to starting your own buisness. I litterally know nothing. Please, give me any advice. Everything and anything will be appreciated. :)))

by West-Albatross-707