Creating a new classroom is simple.
First, click on the Plus Sign button on the top right of the page.
If it's your first classroom, there' will be an arrow pointing right to it.
Next you will be given the option to Create or Join a class.
To join a class, you will need the Class Code provided by that class' teacher or to be invited.
To create your own classroom, click on Create Class.
Then, give your class a name.
The Section line is optional, and can be used in any way you'd like.
When you're finished, click the Create button.
Once you create a class, it will appear on the list under the Home button on the top left of the page.
When you first enter the Classroom, it will choose a generic theme, which can be changed later.
It will have you take a tour where it will briefly explain what all the different sections of the classroom are.
The Class Code is displayed on the top left. Giving the class code to students is one of the ways to add students to your class.