Do you use Divi?, Do you want to change products per page?. If yes was the answer to both questions, you are a lucky one.
Divi peple created a section on theme options:
Once there, we will see someting like this:
And on the field we configure the desired value.
If you don’t use Divi, there is also a solution: edit your theme functions.php and add this line of code:
add_filter( 'loop_shop_per_page', create_function( '$cols', 'return 24;' ), 20 );
Best regards and “may the luck be with you” on your shops.