404 page
404 Page informs the visitors that the requested page is unavailable or it doesn’t exist for certain reasons.
How to set up sections for 404 Page?
From your Shopify admin, go to Online Store -> Themes.
Find the theme that you want to edit, and then click Customize.
Choose Others from the dropdown window -> Choose 404 page.
From the side menu, select Main 404. Configure the default page in the setting on the side with the following settings.