I am going to have friend problems in high school!!!!?

Ok this is sort of confusing but try to follow. I have 3 best friends ever named carloyn, velma, and victoria. Carlolyn and velma aboslutely hate victoria. I kind of can see why carolyn hates her because they didn't get along in elelmentary school, but i have no idea why velma hates her because she has only met her once!!!!! Anyway, in 6th grade victoria went to another school and it has been peacefull without the fighting. however, she has decided to come to my high school in the fall, the same one velma and carolyn go to! i am so scared i will have to choose sides and i dont want to because i like them all. Any advice on what to do??