Hey @MarkSteward ,
Thank you for posting on the Instructure Community!
I recommend creating a custom role at the account-level called mentor, and base it off of either the TA or designer role. You are able to fully customize what these roles can access, including if they can see grades, manage assignments, quizzes and pages (and if so, which they can edit if not all of them), and other things like that.
From there, once you enroll those users into the course, when you open Admin and search people, there is a drop-down box that allows you to search by role, and all the people with that role will appear. You can then click on that person's name, and you can see all the courses and groups they are enrolled in, and what role they have in each of those courses (whether its mentor or something else).
I'll provide some links to guides below that have more detailed information!
https://community.canvaslms.com/t5/Admin-Guide/How-do-I-add-a-new-user-role-in-Canvas/ta-p/99
https://community.canvaslms.com/t5/Admin-Guide/How-do-I-use-the-People-page-in-an-account/ta-p/105
https://community.canvaslms.com/t5/Instructor-Guide/How-do-I-add-users-to-a-course/ta-p/1119
Reach out with any additional questions or concerns!
Hope this helps.
- Noah