If you signed up after August 2014, your username is the email address you registered with.
If you signed up before then, you should have received a welcome email containing your username and a link to the course page you should use to login. Sometimes the email monster moves these to your spam folder, so first you should look there. If you still can’t find it please submit a support ticket.
Found it? Great! Now make sure you're attempting to access the correct course page and that you’re using the correct username. Take a look at the image below to see where you’d find this information in your email.
If the problem persists please submit a screenshot of your welcome email in your support request (so we can find your account) and we’ll get you up-and-running!
Don’t know how to take a screenshot?
Mac users: Press Command+Shift+3, a copy should save to your desktop
PC users: Press Alt+Print Screen, open paint, press "paste", then save