Student accounts are created by Instructors and are based on your email address.
If an account has been added for you, browse to this address to log in:
You should see this login screen
If this is your first login, use the Reset Password option
If your email is in the system, you should receive an email with a reset link like this:
Follow the link to arrive at the Password Change dialog:
Enter your password of choice
Best Practice
Avoid using the same password on this system as you use on other systems.