I'm going to trip a classmate
Why would you trip your classmate?
She needs to get off her high horse.
It is wrong to hurt someone to feel better about yourself. You should find a different way to deal with someone that you do not care for.
I'm going to trip her any way since she was mean to me in 10th grade.
Two wrongs don't make a right.  You do not have to be friends with them, but you should go out of your way to hurt them either.