Try the Gradespace kits
Each kit is a complete WordPress website with its own back office. Browse a demo, book something, then click Look around the admin to see the staff screens. No password needed; everything resets every night and no email is ever sent.
Clinic
An eye clinic: online booking, a diary, patient records and prescriptions, a shop with pay at the store and a till.
Church
A church with two congregations: service times, sermons, events, Plan a visit and private prayer requests.
Music
A music school: tutors, lesson types and prices, online lesson booking, a teaching calendar and students.