Google release a new feature for Google Sites that will clarify how the site is published on the web.
Now you can request that your site is not displayed on public search engines as shown below. By default this option is disabled. If you decide you do not want your site displayed on public search engines, simply check the box.
You can read more about this latest feature on the G Suite for Updates Blog.
Another great feature available is the option to a duplicate a page. If you want to use a layout of an existing page for a new page, you don't have to recreate the new page from scratch. Simply use the duplicate feature to make a copy of the page, rename it, and it will show up in the navigation menu.