In Class Set-up, you can check "Allow Wait List" for a class.

This will set-up a secondary list of members after the class limit is reached.

If a spot opens up in class prior to the start of class, the first member in line will be notified via mobile notification and email. It's first come first serve.

There are currently no settings/limits that can be adjusted for the Waitlist, but we are working on that for an upcoming feature.