The last player who joins an open match books, unless the other player has already booked a court. Whoever books pays the venue and is responsible for collecting each player's share, if applicable.
When you create an open match, you can indicate that you already have a court. If you have, the joining player just confirms the slot. If you have not, the last player to join the match books a court at one of your preferred locations. The player that books the court is responsible for collecting payments from the other players, if applicable.