Instructors can create assignments for their students within Canvas. Assignment pages are a versatile tool that offer a variety of submission methods and other tools, including text submissions, file uploads, media recordings, etc.
Each assignment automatically generates a column in the grade book so the instructor can keep track of their students' grades in one location.
You can excuse an assignment for one student by putting the score in the grade book as EX. You can also exclude an entire assignment from students' final grades.
For more in-depth tutorials on Assignments you can visit the Instructure Help Pages.