In Canada and the US, copyright automatically protects original works the moment you create them (no registration required). That includes written materials, worksheets, videos, slide decks, audio recordings, and course content. As soon as you produce it, you own the copyright.
You can register your copyright with the Canadian Intellectual Property Office (CIPO) if you want an extra layer of proof in case of dispute, but it’s not mandatory. Copyright generally lasts for the life of the author plus 70 years.