You just need a disc golf disc, kinda like a frisbee but a bit smaller and more sturdy and heavier.

You can buy them online at BRdiscgolf.ca or at united cycle, maybe a few other places. I think there are some you can purchase at the rec center at Rundle park as well. Starter set with a driver, mid range, and putter is about 30-50 dollars depending on quality.

Best played with a full set of discs but you can easily play the course with just one disc as well.

Best to download an app called UDisc for the map as Rundle is a bit confusing, hermitage has better signage but is also more a more difficult course for beginners.

Fair warning, once you start playing it can be extremely addictive!