When your trial ends, you will need to enter your payment info and select a plan. You will then be billed at the end of your billing period for the reservation fees.
For long term reservations, you will only be billed for each reservation 1 month or longer in length that spans a majority of the billing period.
You can set up Reservation Fee Rules to pass the fees on to the guest. You can even charge a higher fee and pocket the difference!