You are born an actor! Facts! So, why are you taking classes to learn how to act? You should be taking classes to learn how NOT to act!
Personally, I never memorize a script for film. I do not want to appear rehearsed and too polished to be realistic on camera. Instead, I learn the story and approach the process of acting much in the way we play the game of Gossip as kids: You hear the story, you know what happens to whom and who said what, and then you go elsewhere and repeat it, telling the story to the next person in the most believable manner as possible, even if you make up some of your own parts. I read the script to learn what happened to whom but that's as far as I take the script.