It is possible to have a waitinglist and limited sports for services. You can add that when creating the service.

1. You start by clicking on Add service (how to create a service) and when creating an service option you can set a waiting list and limited spots.

2. You can also set a Max Service Spots for the Service. If you for example have to service options you can have Max Service Spots for both of them. 

In this example there can only 30 players but this Service, so there could for example 10 players buy Saturdays and 20 players Sundays.