Monument 14 is a great book series of three by Emmy Laybourne.
All three books are based around Dean (a 16 year old high schooler, who, even in the apocalyptic world, tries to keep everything and everyone together) and 13 other children who are all stranded together with the struggle of surviving.
The first book has an incredible start “you sort of wish you’d stopped and did those things. Maybe even missed the bus. But the bus was barrelling down our street so I ran.” What happens next? I guarantee you can’t guess.