Below are the various use cases as well as instructions:
Charge Users 1st month full amount
User has a card setup
User has no card setup and will be invoiced the full first month
Charge Users 1st month prorated amount
User has a card setup
User has no card setup and will be invoiced the full first month
Do not charge users for the first month
Should start the billing date on the 31st and create the subscription
Cancel process on the first step after clicking the button, should not do anything