English can be good, a lot of people have done this. Tina Fey was an English major at UVA. Conan O'Brien was a Comparative Lit major at Harvard. Other writers have majored in Theater, History, Poli Sci, Psychology, Philosophy.
Studying great literature, history, foreign languages, philosophy, and psychology can be very helpful for your development as a writer. It's also tremendously valuable to get all the work you can in your college theater - acting, writing, directing, lighting, building sets, costumes. The more you know about the process of going from the written word to flesh and blood performance in front of an audience, the better off you'll be.
Standard advice for film school is to study another subject for undergrad, and then do graduate film school, once you've had a good academic grounding, some life experience, and you're sure this is what you want. I'm not saying this advice is good, just standard. Some people will do better going straight to film school. Some people will do better skipping school altogether and getting any job they can in the business. Waiting for grad school isn't a bad idea, but with the premium the business places on youth, it's possible to wait too long.