Build an app with facility of booking online a particular service provider and a package of related items

This app is intended to provide a particular service to people. In the app, people can (1) select a specific sub-type of the service ( suppose: service is plumbing, its sub-type is tap installation) (2) Then user can view some static written info about the selected subtype (3) book a bouquet of items needed for that service( example: Tap, screws, washer etc.) (4) book the help of an expert if needed ( example: plumber) (5) if the expert help not needed, then there will be recorded audio instructions for the same.