When you first sign up, you will be presented with a quiz to determine your level. You can re-take this quiz at anytime via web browser on your 'My Level' page.
Another way to ensure you are choosing videos appropriate for your level is by going to the tonebase library and using the difficulty filter.
And finally, you can find our "Level System" in the community forums for guidance on which pieces are appropriate for the different levels.
Note: the "All Levels" filter is content appropriate for all users, including beginners.