You will have access to the member portal for as long as your membership is current.
From there, worksheets, palettes, and brushes can be downloaded to your device. You will continue to have access to these if you cancel your membership, but will not be able to re-download them.
Videos can only be watched while logged into the member portal, so you will have access to those only while you have an active membership.
You can cancel anytime, it will renew monthly until you do so.