Use MyCourses to make slides and other material available to your students, and use Zoom to deliver lectures with copyrighted content.
For print material for which you cannot find a suitable digital substitute, follow the guidelines for how to create a scan of your print course materials and post to myCourses
Your Subject/Liaison Librarian may be able to help you find alternative content, and the WorldCat Discovery has a large collection of online journals and ebooks that can help support online learning. In fact, many content providers have recently increased access to a variety of materials to ensure broader access by campuses. Your librarian can also help you find openly licensed teaching materials like Open Educational Resources (OER)
Sharing audiovisual material like films and audio files is more complex. But remember you can still link to legally posted online content (from YouTube etc.). McGill Library subscribes to several video streaming providers which offer a wide range of films, documentaries and videos that you may link to