Advice for finding cheaper rooms/apartments to rent near campus?

Excluding on-campus residence and the Quad, I’m looking for a room or apartment to rent from late August onwards. My budget is $900/month. Preferably within walking distance.

I am just generally unsure of what websites (such as rentals.ca, Kijiji, etc) or apps to search as I’ve never gone about renting in Toronto before.

Any help would be greatly appreciated! :)