a current student here
We have two Tim Hortons, one nearby the library/next to the art gallery and one at the student center.
At the student center, you're more than likely to get the varieties of Tim Hortons to buy from like you'd normal get at the usual Tim Hortons.
We have two cafeteria. The one in the student center and Tim Hortons, they provide different meals and options for you to pick. They do have vegetarian options and some healthy choices as well. They make plenty of sandwiches, provide snacks and desserts, and different drinks to have milk, juice, pop/soda, energy drink, water (varies), and tea.
If you're interested for the healthier types, then the upstairs cafeteria would be a wise choice. It's like one section is similar to subway, only you can pick as a sub/sandwich/bun for your main meals. They have desserts that are either sugar free, gluten free, or no fat. There's a salad bar you can make of your own like fruit salad, lettuce salad, egg salad, etc...
They do have desserts like brownies or cheesecake or cake. Cookies as well - I would suggest the school made, it's delicious from what I have heard.
If you get yourself a meal card, you're saving yourself some money because you won't get taxed on. All you need is to start with $25 to have a meal card.