It depends on the extent of your project. For example: >> CLI phone register. 1. take input 2. save it in an array. 3. create a do while loop for menu based program. >> CLI phone register with storage 1. Create a menu based program for entries. 2. Save them in a Database or file. 3. Read that file at the start of your program. >> GUI based phone register 1. Create utility functions for each module. 2. Create GUI using TKinter or QT. 3. Attach the utility function with GUI for functionalities. >> Web based phone register. 1. Use flask for backend and business logic of your program. 2. Use HTML5 and JS for frontend or any other specific frontend tech like React, Vue etc. 3. Use Rest APIs to connect frontend and backend. You can also use Django for web development.
We can help you but it's better you try it yourself...