Hi Joe,
Actually the initial video on the cycle of 5ths is meant to explain how the cycle of 5ths is the basis of functional harmony. As far as when to use it to practice, I think it’s way to early in the course. You will need to learn all 7 heptatonic fingerings for any given scale or arpeggio in order to correctly practice anything through the cycle of 5ths. So, don’t worry about it for now. Just try to complete the assignments in the order they are prescribed in the main lesson book which is also the order in which the videos are introduced in each module.
Let me know if you have further questions!