New to Rover- How does booking/requests work?

I currently have my first request, and me and the owner have talked and had a public meet & greet with the pups. We've set a date for the meet & greet in her home, but it's over a week away because of our schedules. The request expires in about 48 hours. If the request expires, what do I do? Does it matter if it expires? If I modify a request does it extend it? If I archive it can I still access the chat, and book it? Does the owner get notified when I archive it/let it expire/do anything?

I just want to understand the interface better, and I'm nervous that while I get to know it I'll appear unprofessional.