Re-occurring bookings - how to make he process faster

My issue is our classes mirror school term times with a gap in between when it's school holidays. Therefore I need to set up new classes each term via scheduling which is fine however it means I'm booking each individual client onto their group session also (we have 150 clients so it takes me ages). It's more or less the same clients each term. Is there a way I can import these clients onto their new class booking without duplicating them? And also show if they have paid or not and send them a confirmation without having to do each one individually?