It is possible to teach dance performing and dance fitness at the same time, but it is not recommended. It is better to choose one lane and focus on that. If you want to do both, then offer different classes.
For dance-performing classes, advertise them as being about learning how to perform on a stage and impress an audience.
For dance-fitness classes, focus on the keep-fit element and that it is for more basic movements suitable for all levels of fitness and abilities.
One strategy is to offer your fitness class as a step one and your performing class as a step two for more advancement. Be careful not to imply that the fitness class is for bad dancers or is less important.
