Building a White Labeled Website with Variable user type logins

I want some recommendations about handling a new project which is a white labeled website. The website will load with different colors depending on the URL that is used to access it. The URL will also set the type of users that can login. Example: default URL : schoolsystem.com if i use students.schoolsystem.com then i need to restrict access to be only on student login if i use teachers.schoolsystem.com then i need to set access only for teachers user type.

My questions start at how can i implement these URLs knowing that i may have more types. I have my own server where the website will be installed but it should be accessed by internet and not just locally.

Thank you for your help :)