It's actually super easy! Once your school or district has properly installed the LTI for the teachers and students, you have to click on the Shmoop module and/or the assignment. <== All of this is configured by your school/teacher within Canvas. If you do not see this, you will need to reach out to your teacher or Canvas admin.
Once you click on the link, it will redirect you from Canvas to a new tab over to Shmoop. It will say "Creating a new account" and automatically create a new account within Shmoop. You may need to select your school if it is a district account with multiple schools. That is shown below:
Just choose your school, and select "Join License" -- That's it. Now, get Shmoopin'!