ERPNext 15 List of Modules

Hi I am developing a project using Angular V18 that has some features and modules of ERPNext V15.
The modules I know are HR, Payroll, Users (Non-Module), Stock that I want to implement into Angular. But I want five of the most used/popular modules of ERPNext. Can anyone advice on this? The project is only for demo purposes and internal use.
Furthermore, DocType in ERPNext is very useful so in Angular how can I create a dynamic class that is like DocType which can be reuse to create modules and so on?