Is there a gym owner forum? It is better to have some business methods on it.

No, if you want to learn the management of stadiums and gymnasiums, I suggest you buy a copy of "Practical Operation of Sports Leisure and Entertainment" written by Cai Jun, director of the Sports Industry Teaching and Research Section of Xi Institute of Physical Education. Professor Cai spoke in more detail. Note that it was published by Shaanxi People's Publishing House.