Please notice that: There are 02 ways to setup Homepage layout for your site:
From your Shopify admin, go to Themes > Customize > Sections > Add Section:. This way you can create your own homepage by choosing the sections you want. But if you use many sections, it will take time to load in admin page.
You can import Homepage layouts from the Preset below. This way helps your admin page load faster.
To import the settings data json for Homepage Layouts, please follow below instruction.
Download the corresponding setting data json with homepage layout you want.
Open downloaded file in the text editor.
Select ALL and COPY
Go to Actions > Edit Code
Find folder Config > Open file settings_data.json -> Select ALL and delete. Paste copied preset from external file.