Hi @JessicaDening ...
Your best option would be to contact your University's Online Learning / eLearning / Distance Education team (or someone who is a Canvas administrator at your University) ... as they would be able to help get you unenrolled from that course in Canvas (or at least tell you how long it may take to get you unenrolled). Then, you would not receive those notifications in Canvas.
But, for the time being, you can configure individual Canvas course notifications by following the steps in this Guide:
How do I manage notifications for a single course?
Hopefully, this should be of some help for you. And, hopefully, you'll be able to get in touch with someone at your University soon. Good luck!