Always Available, Always Allowed: Open Access Materials
While traditional copyright protections can get in the way of including paywalled articles in your Canvas shell, there is a lot of research available to you right now for immediate course use.
Scholarly works - research articles as well as textbooks and other course materials - can be given an open license to encourage wider reading, citation, and reuse.
Government research is often publicly accessible as it is taxpayer-funded.
If you find something in an open repository, published by an open access journal publisher, or published by the government, you can feel free to incorporate them into your course once you verify the access specified in the license. Or, in the case of materials in the public domain, use it however you like!