PREREQUISITE: You must have created a Class before assigning a Course. From there, you may assign a Course to that specific Class.
Click into a Class
Click the "Add Courses" button
From the popup, select which course(s) to add to that specific class. You may also use the search function
Select the Course you would like to assign by clicking the "Add Course" button
The course you selected will automatically appear in a list of "Assigned courses"
*NOTE: All of your students in that Class will automatically be enrolled into that Course.