"Life coaching" is vague. "Weekly accountability calls for freelancers building a client base" is something a specific person actually wants.
A client should be able to see your real availability and book directly — every extra email exchanged is a chance they don't follow through.
Single paid sessions work well starting out. An ongoing monthly subscription builds more predictable recurring income once you have a base of clients.
Buylib lets clients book directly from your real weekly availability, with no double-booking possible even if two people try at once. Sell single sessions, or turn ongoing coaching into a subscription billed automatically — both from the same store.