Bodyweight exercises are great, but only if they follow basic training principles to form a complete, well-balanced exercise program.
You won't get the individual attention as you would expect of a one-on-one session, but group training is an economical way to get coaching.
Taking into account physiology and all other aspects of exercise, it becomes clear how much (volume) and how often (frequency) you should be training.
Progressive overload is the process of gradually increasing stress loads, pushing your body beyond its comfort zone by overloading your physical systems.
Periodization and cycles have become an important principle for continuing progression, and to ward off stagnation, boredom, and burn-out.