Film making sounds fabulous! I am not sure how long you would have to be in school exactly, but at least a four year degree. Important is to look into a school that has network and connections such as Full Sail or New York Film Academy. Keep in mind, this field is highly competitive, so be sure to NETWORK, NETWORK, NETWORK. Rub elbows with everyone and anyone that might help you started and intern, volunteer, get as much experience under your belt as possible.
Develop a portfolio of all your works to show your talent when applying because most undergrad programs want to see some of your work to accept you into their program.