Please first have your Turnitin Class ID, and Enrollment Key, both given to you by your lecturer. If you are a new student, and have created your account with the new class, then you already created the class, and do not have to enroll in that class. This is for additional classes.
1. Login into Turnitin with a student user profile.
2. Click on the enroll in a class tab on the student homepage.
3. Enter the class ID and enrollment key for the new class.
4. Click submit to enroll in the class and add it to the student user homepage.
A video on how to enroll and join a class: