How to begin a story?

hello im 15 years old and i love writing story's, i need some help to write properly because i really want to write at least one full book. so if you can give me some good advice and tips then that would be great but a question I really need right now is how should I start the story. I mean must all story's start with action because one of my teachers wont even watch a film if there is nothing exiting within the first ten minuets. i had started then heard my teacher say that so im on the brink of throwing my story away and starting again.