Your property name is the umbrella term for all of the sites you have on Hipcamp. If you have multiple sites or site types -- like cabins and tents, for example -- they are all under your same property.
To edit your property name, go to your Host Dashboard > Property > Edit property details.
Once you click Edit property details, you'll be taken to a page where you can update your property name and description.
You can find more information on naming your property and what to include in your property description here: How do I update my property page?