I think it's great that you want to be an entrepreneur! I was a lot like you when I was in high school and college - I had dreams of starting my own business. I've now done that a few times. It's a lot of fun (but stressful too).
Getting a degree in business sounds like a good plan. Before then, there's a lot of great material about business, that you can access without even taking a course (you'll find that this content will be useful to read while you are studying business at college as well as after your career).
I would suggest reading blogs or books about fundamental business topics - marketing, sales, and the like. The other type of content that I found very rewarding (and motivating!) was to read books about entrepreneur journeys. Things like biographies about entrepreneurs or people who built things. While you won't learn about business fundamentals from these things, you will find inspiration and motivation from what these people have done.
All the best!