toxic friends at school check.....

i got told that i am not friendship matrial because i have a guy friend that she likes and she told me i need to stop talking to him cuz im trying to take him from her.....how tf

Well...It is not your problem, but her.
She needs to stop being so mean

that is what i thought

It is your, and only your decision to whom you talk . A friend would never question such an obviousness.