Class Types
Your class types tell the system what kinds of classes you'll be teaching.
Find Class Types in the Setup menu at Setup > General > Class Types. The page should look something like this:

To edit or delete a class type, hover over the class type and click the blue down arrow on the far right. This action displays a drop-down list with both the "Edit" and "Delete" commands. You can also edit a class type by clicking the class type's name (e.g., Ballet). This action takes you to Edit Class Type (shown below).
You can use the drag-and-drop icons to change the order in which your class types will appear. Hover over a row to see the drag-and-drop icons.
Click the "Add" button to add a new class type. You will be presented with a form to fill out. Enter the information about the class type and click the "Save & Return" button to add the class type to the list.

When you edit a class type you'll notice that a class type can be set to "inactive" by unchecking the "active" checkbox. An inactive class type can't be used for creating new classes and won't display on your website. Any active classes using this class type will still display on your website.