Comment out the Sub Categories block from the classic template

By default the category page shows  a sub categories block that often just gets in the way of getting straight to the products.

In your child theme add the following folder path

/childtheme/templates/catalog/_partials

Download the subcategories.tpl file from the /theme/templates/catalog/_partials folder

at line 25 edit

{if !empty($subcategories)}

 to 

{if !empty($subcategories) && 1 eq 2}

Makes the _partial/subcategories.tpl add nothing (never becomes true), and the subcategory block is removed from the category page.

Upload the revised .tpl file to /childtheme/templates/catalog/_partials so that it will override the classic theme.