Not bad for a first story, Syd. I would recommend changing the plot though, like adding a new mission that didn't really happen in the series. You could change which characters were present in which missions, or add new characters to your own mission you imagine. The series is your own slate now, and you can dictate what happens, where. Do anything you want. Just try to stay off of rewriting the cannon story. Also make sure to credit it to the all mighty Hiro Mashima, or copyright will claim your butt. Happy writing!