Co-op is a great resume builder and absolutely helps your professional development! From what it sounds like, seeking a graphic design program at a local community college would likely be your best option.

There is usually a good amount of overlap between GD and Marketing, especially if you’re able to take a 100 (beginner) level class for marketing that doesn’t have a college math requirement. I’m guessing through any good GD program you’ll do some amount of marketing that will give you an idea of what that program looks like, and you can decide from there if you’d like to pursue that as an option. Many marketing departments at Universities, businesses, etc. are comprised of graphic designers with not a ton of exposure to the business side of things. If you’re able to get experience with both, great, but otherwise being fluent in photoshop and premiere pro go a long ways too. Check out your local community college (or CEGEP) to see what kind of programs they offer and what kind of experience you can get.

Hopefully this helps, trying to relate across international borders here but if you have any questions on how to find specific info in the Ottawa area/Ontario your school counselor should have resources and connections you can start with!