If there was a book that I would recommend martial artists to read to get themselves on track to run a successful martial arts school, it would be the The E-Myth Revisited: Why Most Small Businesses Don’t Work and What to Do About It. The main thing that sticks out to me is the fact that you, the expert martial artist, is only the technician. It doesn’t automatically mean you’ll become a successful business with just that. Learning management is the journey and as a martial artist, you should know it is one you already walked.
If you’re looking to improve yourself as a business person, this book is one I recommend to you. Translate your training more purposefully by learning how management works.