Writing The Birthday Boy

I'm trying to write this script for a slasher movie but I just feel silly. I feel like nothing I write sounds natural!!! There's so much that goes into making a movie that I hadn't even thought of, we had to cancel our shoot because we forgot chairs. 

Kinda just ranting here but I just want this to be good. I guess I'm just doing it for fun, but I guess I can't stop chasing the idea that everything I do has to be great. Do any of you understand that feeling or am I crazy lol