In addition to selecting a major, there are minors and certificates to explore as well. You can explore Entrepreneurship, Sales, Advertising, Communications.
I do think layering a minor or certificate in with your overall major would be very helpful. Especially if you know what field you want your business to be in.
In my work experience, which started with my work in small start ups and led me to ultimately a career in a very large company, the following are the most critical skills for success:
1. Ability to sell - If you are good at selling, that is critical, as even the most amazing product likely won't sell itself
2. Ability to communicate (Market) - Generally to enable sales, you need to know how to get your message out there
3. Deliver & Support the product - If the customer has a terrible experience getting or using the product, you won't be very successful.
4. Finance - underpinning all of those is a good understanding of how money works in your company
As noted above, a Management degree would provide you a lot of opportunity to explore Sales, Marketing, and Finance. Deliver and Support is something that would be very unique to whatever your business would be.
Of all of these areas, but again, only if interests you, I would say Finance is the critical one. Your business needs to make a profit, if you don't understand what is required to make that happen, you will need someone you trust to advise you in that field, as it is critical.
I think it is great to have a goal of running your own business, I wish you all the success in pursuing your dream.
i think Kaitlyn offers a great answer on your college options, but I would also consider making sure you are looking into educational options that are generally of interest to you. The reality is there are some many industries and in general, businesses typically benefit from someone that knows the industry to "run" them. So rarely, are you just going to be able to get some education and then run a business. Typically you need to acquire skills to know how businesses are run and then apply education whether self learned or through management school, etc. to then move up. Usually if you are doing a great job within a company, you will be afforded opportunities to gain more management training, career advancement and opportunities for on the job training. I would take these aspects into consideration as you look at the future.