You can manage categories while creating or editing a lesson.
Kinderlime has provided a few sample categories, shown below.
Click on the blue "Manage Categories" link at the bottom to open the category editor.
Use the ellipsis at the end of the row to edit or delete a category.
Click on the blue "Add Category" link at the top of the pop-up to create a new category.
Use the floppy disk icon (circled in pink) to save your new category, or the "X" to cancel.