Put a term of classes on sale as one block booking. Parents enrol and pay once, and every session is booked for them.

Set the term dates, a block price and a capacity, then publish.
Existing families get first refusal before places open to the public.

Sell the whole term as a single enrolment, and watch the places fill.

Set the start and end of the term once, and the sessions fill it. Each child has a place held on every one.

30 days of Pro free, no credit card. Most clubs are taking payments the same day they sign up, with courses & terms and everything else included.