If your course has received a new course code and you want to copy a previous reading list to the new course, you need to contact the university library.
In most cases, this is because you haven't created a library account with the university library. It is through this account that you gain access to edit reading lists. Please contact the library to have an account created.
If you can't find your course room in Canvas, it might not have been created or published yet. Contact the Canvas superuser at your faculty.