@AnneNoble-Custe ...
Thanks for clarifying that you are using the Free For Teachers (FFT) version of Canvas vs. a paid Canvas environment (which would normally be purchased by a school/organization).
Normally, you would go to your "People" page of the course and then add your students to the course via e-mail address. Then, they would be able to sign in to your course that way.
How do I add users to a course?
There's one other way that might be worth checking out...which is self-enrolling. In your course, go to your course "Settings" page, and then on the "Course Details" tab, scroll to the very bottom of the screen. Underneath the "Description" text box, click on "more options". The very first check-box option you'll see listed is "Let students self-enroll by sharing with them a secret URL or code". If you select this option, you'll need to click on the "Update Course Details" button. Then, return to that area of the screen again near the check-box, and you should see a unique URL which you can give to your students. They would need to go to that URL and complete the sign-up process to access your course.
How do I enable course self-enrollment with a join... - Instructure Community (canvaslms.com)
I hope this will help a bit!