That's amazing! I hope you have a blast playing it!
As for the playbook differences, the Expelled is about never having a safe or stable home (and thus finding home amongst the other Kids), the Miscreant is about challenging existing rules and systems (whether it's beneficial or just plain chaos-causing), and the Punk is about fighting injustice and standing up for the downtrodden (and how one's ideals may have to change to fully do so).
Each playbook has an italicized character blurb at the top of the page and an explanatory block at the top of the middle column if that helps too!