You are able to have 6 standing reservations at any one time. Once you have checked-in to a lesson you are the immediately able to book another. Alternatively, you can cancel an upcoming reservation if something more appealing pops up!
You are able to view lessons 2 weeks out. You can view your upcoming reservations either through the app or the website, and can cancel them from either as well. Remember that you can visit each location 4 times per 30 days.
Not sure where you stand on number of visits to a certain location? You can monitor this via your Account Settings tab in the app. Past, future and missed reservations count in this number so keep that in mind!