To confirm, you need the ressie confirmation number and the phone number you placed for the ressie confirmation - usually a cell phone number since that is what you have on you when you are there.
At the end of your session, it allows you to enter an e-mail address for them to send the confirmation. If you didn't ask them to send it to your e-mail address or you didn't copy down the numbers, then you will need to call to confirm.
Also, another little hint - I put the ressie numbers in my calendar in case I needed them when I checked in at the hostess desk. They just asked my name and what resort I was staying at to confirm it was indeed me!