We don't do cheerleading, but I recently heard a news item on the radio concerning injuries in cheerleading and it mentioned that there is some kind of national professional association of cheerleading coaches or businesses, something along those lines. You know-- the kind of organization where people in the same business meet and exchange ideas, and maybe even approve or "accredit" those in the industry.
Try to find such an organization. It might do accreditation for cheerleading training businesses such as the one you want to open. In ANY activity, I would want my child only to participate in something that had the backing and support of a larger, professional association. This group may for instance do training of people like you, so you can put on your business that the director and teachers are "Cheerleading Coaches of America trained instructors" or whatever (I'm making up that name). It gives a business a far more professional tone and makes parents far more comfortable if they see that the director/owner/coaches are trained by an outside group and not just doing it solely on their own experience. (Not that there's anything wrong with your own experience, I'm just saying what makes many parents more comfortable is knowing that an independent, outside group has trained and/or monitors this person/business.)
Will you need a license to do this? Is cheer considered a "sport" in the eyes of the law in your city/county/state? If so -- what does that mean for your business?
What legal liabilities will you have even if there are waivers? (If not perfectly writtten, a waiver still can leave you open to being sued, so get a good lawyer involved and get tips and samples from others already in this business--that's a good reason to become part of a professional association, to learn from others in this industry.) What types of mats and other protective gear do you need to meet standards and, again, to avoid liability? What agency of your city/county/state would inspect your facilities, if any?
In anything where kids potentially could be hurt, you have to have all those ducks in a row before you let the first kid in the door. Oh yes -- and check out insurance as well. You won't be able to operate without it and need to account for the cost of it, which could be high.