How To Create Two User Groups in Firebase Web

I am developing a web app which uses Firebase Authentication and Real-time Database. The sign-in method is via Google and then if the user is new he/she will be ask if whether he/she is a teacher or student.

Teacher: can create classrooms and add students using their user.uid. Each classroom has a unique classroom id. Can view the list of their students.

Student: can view their classroom, and classmates.

So How do I code two different types of users in Firebase for my web app? What will be the rules to use in the database?