How a booking works
You choose a rate and a duration and pay by card, and the booking closes when the payment goes through. The rental starts at that moment.
There is no host approval and no waiting for an answer. The host is notified of the booking and is not required to approve it.
From the moment the booking exists, the dates you chose are blocked on the listing's calendar and nobody else can book them.
After the payment goes through, the exact address and the other side's phone number open, inside the conversation about this listing. Before that they do not open.
The host can cancel a booking they cannot honour, and so can you. A cancellation releases the dates and tells the other side.