Delete a Canvas enrollment
For a person to be removed from a Canvas course, they must be removed from SIS. If not, they will be re-enrolled anyway as a result of the automatic process between SIS and the LMS. The only way to alter enrollments in live courses in Canvas is through the SIS process.
This document details the removal of a user from a course.
Enrollments in Courses in other "instances" of Canvas (such as "Training and Development") can be managed by Teachers via the People tool.
If a course is appearing on your dashboard and you would like to remove it, you can "un-favorite" it by following the steps available here: https://community.canvaslms.com/docs/DOC-10570-4212710327
For more information regarding the process between SIS and Canvas, consult Courses Do Not Show Up / My Course is Missing