The detail to resolve first
Allow for getting from the vehicle to reception as well as driving. An appointment end time does not necessarily mean the passenger is immediately ready outside. Agree how the traveller will notify the driver when leaving a meeting.
Prepare a workable enquiry
Put appointments in time order. Identify the meeting that cannot move, the person coordinating changes and the contact at each venue.
Check the written arrangement
Ask which parts of the itinerary are included, how waiting is handled and what to do if the schedule changes. Identify any tickets, guiding, specialist assistance or extra stops that require separate arrangements.
Keep the written confirmation available to the passenger. An enquiry or a WhatsApp conversation is not a confirmed reservation until the specific journey has been accepted.