On another post in this forum, a sitter wanted to charge for a meet and greet. You can try to do that. Be prepared for pushback because it’s more common for the meet and greet to be free.
The purpose of a meet and greet is for both parties (client & sitter) decide If it’s a good match.
I would not charge for a meet and greet, because I have met dogs that were not a match and let them know right then and there, no booking happened. If I had charged them for the meet and greet, I don’t know how smoothly that conversation would have gone.
Side note: you can meet wherever you want, but I prefer places with little to no other stimuli, so I definitely would not meet in a dog park. Usually if it’s for housesitting, I meet near their home and if it’s for boarding, near mine. Rover used to require posting photos of your home and yard/area where walk/play for potential clients to view.
Words of wisdom: Be prepared. Some pets nerves impact them when staying away from home. Even for trained adult dogs: There may be a lot more barking, whining, pacing, peeing indoors, door darting, and other destructive tendencies. Most experienced sitters would likely advise: Have pet gates, or indoor playpen, or indoor fences, urinary belly band wraps, possibly diapers fitting sizes of all dogs you'll board available, as well as extra bowls for water/food, beds, leashes, collar with tag with your emergency phone #, and really closely evaluate any security threats in your yard. Also, It benefits you to plan to stay with the dog and not leave it alone in your home for a minimum of the first 24 hours. Some dogs can’t be left at all without either destruction to your home or themselves having issues. That means taking care of everything you need before those dogs arrive.