Hello, I would like to develop a plugin that can manipulate user registration page. What I'm trying to do is to change the input form of the user registration page. For example, I would like to receive additional information such as user phone number, student ID, birthday, etc. Then I send a registration email using that student ID to make sure the user is the member of my campus.
What files or hooks should be used to do this kind of work? Do I also have to change the data input model to database?