It is necessary to implement the ability to make records to clients

Here is a form https://b315226.alteg.io/company/61082/menu?o= It is necessary to implement something similar for recording clients, for example, from a form. So that a person could choose a master and time for the procedure. Services can be different and can last for a different amount of time (can be implemented through the selection of a certain category of products and additional fields for the number of hours per procedure). It is important to take into account that there are already records for procedures in the form of processes in the masters and you need to show only free records. How many hours does it take to implement this?