Set up Tessitura 12.5.1.216 to accept advance School Bookings without having to take payment at the time of booking

Our current set up for admission, groups, members has us unable to Save a transaction without first taking a payment.

we would like to start booking our school visits in advance...create an Order Number for them so they can be brought up on the day of the visit to take payment then...unfortunately we cannot SAVE the order without taking a payment...

any Step by Step on how to do that?