I’m taking over a timeslot with a new class format….Any suggestions on how to “win” them over?

Enthusiasm for the members and the format
Presence / confidence
Very clear instruction
Clear communication of the purpose of the class

When launching a totally new format, represent it in the best way possible, so that people have a good idea of what it’s about. Some will like it. Others won’t. Some new people will try it. It will build on its own over time.