Default attendee role

By default, everyone joins the session as a participant. Session owners and course instructor join as a moderators. Use the Default Attendee Role menu to change the default for guests and students. 

You can't change the default during the session. But if there is no end date for the session, you can change the default before the next time you use it.

Make sure you understand the different roles and their permissions before making any a default.

More on roles and permissions