You can create as many classes as you like. And as many students as you want can join any class. When you sign up, a default class is created with your name.
To add a new class, click the green box, Create New Class, on the top right corner of the page. You will be given an individual Class Code for each class you have.
The Class Code will be located at the bottom of each class section.
Teachers employ different strategies for naming their classes, such as "Period 1", or "Life Skills". Use whatever you like.