If you are in the wrong classroom, or you want to leave a classroom that is not active anymore, you will need to ask the teacher of that particular class to help you with this.
You can share these articles with them for instructions about how they can help: https://support.edpuzzle.com/hc/en-us/articles/360009934972-How-do-I-remove-a-student-from-a-class and https://support.edpuzzle.com/hc/en-us/articles/360009934912-How-to-move-a-student-to-another-classroom