Bookings Piorities

There are many incidences when there are at least 2 more client prospective clients who actually asked for quotes for wedding on the same day but the enquiry was at least a few days apart. We are focused mainly on first-come-first-serve, meaning we will be "booked" only when the client paid the deposit. But what if the 1st client who approached us but have not paid the deposit but the 2nd prospect wants to book us but has not paid the deposit as well?

We will have to look at the packages because the priorities will be given to those who book a full day package or a complete package (photography + cinematography) unless the 1st prospect says "no", then we will get the 2nd prospect to book our services instead.