Hey @spon, once you've downloaded the app to your desired platform, navigate to the main menu, then "Login - Sign Up" and from there you can register 🙂 Billing for the subscription is managed via the App Store / Google Play store, depending on which store you use and have an account for. Let us know how you go!
Hey @spon, billing is actually managed on the App Store side, a bit like other apps you may purchase through the store. The subscription itself is attached to your Apple account that you use to access and use the App Store, and so the subscription including all billing information can be managed directly through the App Store. You can't add payment details or the like within the app itself, it needs to be done within the App Store. Hope that helps!
If you were to cancel today @spon, you'd still have access until the end of the free access period 🙂
Which part did you need us to confirm @punter257?
If you've cancelled before the end of the free period (the 1st of September 2018), you'll have access to content up untill this date.