Hello
As per my understanding you are looking for a Drupal Expert who can assist you with Booking Module so that users can book the tennis court as per the time availability.
We can deliver you a Module which will set-up schedule for Venue, so that users can book slots within specified opening hours.
There are two approaches to achieve the desired functionality one is to use an existing module & customize it as per your need or we can custom develop the module & then integrate it within an existing site.
We can customize its any kind of an existing module,plugin or functionality & also can custom development.
I would like to tell you that I am working on Drupal Platform from last 7 years.I have worked on its various versions such as D5,D6,D7 & Now Latest D8.
I would love to discuss the work with you. If things work we can go for long term business.
Please initiate chat so that we can discuss more and I can suggest you better.
Kind Regards
HS Virasat Solutions