After you have created a new Group for your students, you'll need to add content to that Group.
First, click on the Assigned courses tab on the left hand side. Then, click on Search Library.
You will then be re-directed to LingQ's library. First, make sure you are in Courses View (not Lessons).
When you have decided on a course, click the three dots at the bottom. Then click Add to {Your course's name].
That's it! The course has now been added to your Groups.
You can see which courses have been added to your Group by going back to the Assigned courses tab.