Hi @TerriWiley
The attendance tool automatically populates the active students you have in your class.
If you go "people" you should see the list of students there. You either have no students in this class or you might have multiple sections and a section with no student.
In this case, make sure on the attendance page, you have the correct section selected to display. If you have a section with no students, no students would show up.
Also, keep in mind the students need to have an active role in the course. If they are inactive or pending they won't show.
Here is a guide about Attendance.
How do I take roll call using the Attendance tool?