what to do I don't want to fight

I'm 17 years old and I'm a senior in high school. I'm not a bad kid I don't start thing with anyone yet ppl always want to bully me for different reasons. There's a girl who has been going around the school today saying that she will beat me up after school and I'm not a fighter so I'm really scared. I don't want to tell the principle because I'll look like a wimp or something. I don't want to fight what should I do 😞 I have never got into a fight in my life and she is known for beating ppl up around the school