Use the Attendance tool to track attendance. You can define attendance statuses (e.g., Actively participated, Attended, Did Not Attend), assign points/percent for each, view attendance results, and track users with poor attendance.
The Attendance tool is NOT connected to Grades, so you must add an Attendance column in Grades to enter values.
Video from Donna Simiele on how to add a customized Attendance Scheme and use the Attendance Generator App. Donna has an Attendance for Brightspace document associated with the video if that is more helpful. Both also have a QR code to a handy "Bulk Date" tool to save time entering dates.