The green screen process can be fun and creative...if you take the time to plan well ahead of time. You'll want to write a script and practice it, think about what images you'll want "behind you" as you record video...dress up as your character...shoot the video in front of the green screen...then edit the whole thing together using iMovie.
What makes this project more challenging than others? Details...you'll need to pay attention to the cropping of video...quality of video and audio...curate quality images...video processing and editing...exporting and publishing. Then there is the whole challenge of working efficiently...in the green room and editing your video!