The "Home Page" is the top page of your site that appears when you visit a URL without a path.
If it is not set, you can set it by selecting "Home Page" from "Page Type" that can be selected in the upper left of the editor.
You can also set it by leaving the path blank.
To change the "Home Page" that you have already set, first change the type of your current home page, and then change the type of page you want to be your home page.
Please check the link below for more information about page type.