In order to find your Class Code you'll need to log into your teacher account. Once you do click on 'studio' at the top of the screen, then choose the correct class from the drop down menu under the word 'classes'.
Now click on 'students' on the right hand side. Once a list of your students appears click on the 'add or invite students' link. Two options will appear for adding and inviting students. Click on the 'my students will create their own accounts' option and your class code will appear. (As a tip, your class code is the same as the password for the Private Parent Showcase!)
Your student can then sign in and enter this code on their 'class' tab.