A homepage is the main page of your website, the address of which is your root domain:
The address of your homepage is my-domain.com
Meanwhile, the address of any other of your website pages is: my-domain.com/contact or my-domain.com/about
You can set any page as a homepage in the general page settings. Simply open the website builder, and expand the Pages and navigation panel on the left:
Find any page that you want to be the homepage of your website. Open its settings and select Make homepage:
Once you set a new page as a homepage, the home icon appears next to its title. The previous homepage becomes a regular page:
You can also rename the homepage (and other pages) in the page settings:
To change the order of your pages, drag them up or down by the handle: