Hi Melissa, it’s great to see you reaching out and seeking some ideas from other professionals. We are always learning!
Per your question, it is my opinion that the most effective general group training should be done with body weight only and in a functional manner. Teach different variations of lunges, squats, push ups, core training, etc. There are myriad exercises to select, but in the long run we want to do what is most beneficial and minimize risk of injury.
Music wise? That’s up to your clients! =)