What a beautiful place you have, @Philippa3! Yes to everything @Andrea9 said, and just so you know, a quick way to tell whether your message has gone out is to take a look at your dashboard. Go to Host at the top of your screen, pick Dashboard from the dropdown there, then Inbox in the grey bar just under Host, Trips, etc. Beside the name of the guest is your conversation with that guest. If your message shows up there, it went out to the guest. They don't always respond, but at least you know you did in fact reply.
Go back to Dashboard and make sure it is not alerting you to do something - like Accept or Pre-Approve. Follow the prompts for those. Don't leave them to expire. Again, do familiarize yourself with the terms. Take Andrea's excellent advice. All the best with hosting!