If you see someone being bullied, do something! If you aren't part of the solution you are part of the prolem. You should try to get the person being bullied away from the bully and notify an adult or someone of higher athority. If the bully follows you try to just calmly let them know that what they are doing is not okay.
I you are being bullied try to ignore the bully. The bully may stop when they see that you aren't reacting. If the bully doesn't stop notify someone of higher athority.