Students will need a Classroom URL and Invitation Code to join your classroom. Each classroom has a unique URL and invitation code which is automatically generated when you create the classroom. To find the unique classroom URL and invitation code, enter your desired classroom:
In the top left navigation panel, you will see the second option to "View Invitation":
This will open up a new window with options to copy the URL and invite code to your clipboard and provide to your students to join the classroom: