How do I get hold of the host's address?

As soon as you've validated the confirmation of your booking request and your payment has gone through, you'll gain access to all the information related to the accommodation.  (address, host's contact details, etc.)

You can also communicate with your host through the internal messaging service for more information on how to get there, to confirm your time of arrival, ask about sports activities in the area, check the weather, and so on.