Every account, whether student, teacher or admin has a link to your referral scheme at the top right of their dashboard.
You can incentivize every user to bring in students. Students who sign up through the specific login link will be "credited" to the referee and your school can track and incentivize your best promoters.
Referees can also track their progress as it lists at the bottom all their referrals.
As an administrator you can track the referrals in your school inside your admin dashboard, by clicking on the "Referrals" page in your side nav.