Disclaimer: I am no professional. Follow advice at your own risk.
By: An ex-victim of bullying.
Of course, first step and utmost important if you are being bullied. NOTIFY an authoritative figure. Principle, counselors, a teacher.
Mostly because if anything shall happen in the future, like a lawsuit. You have evidence against the bullies.
However, I found out that unless you stand up for yourself, the problem will not go away.