I would start with a really great client management software. I like www .fitify.me make sure you use one that will let you post your schedule so you can run your classes in multiple locations. Also having the ability to collect multiple forms of payment will help branding you into a legitimate business. This software lets your clients book into availablties on your scheduel, it also lets you sell sessions in blocks to each client and remembers how many have been redeemed. Make sure you can organize and contact all those people that took your sessions in the past. I like Fitify cause they are really good to the little guy, they don’t cost much but they really bring legitimacy to any one person business like a personal trainer or palates, yoga & zumba instructor.