Hi Filipe,
Nowadays almost any browser has developer console. Click on product with right button and select ‘View Code’ or ‘Inspect element’. You will see DOM tree, mouse over any element and you will see it is highlighted on the page. This way you can find what selector is used for products in your theme.
PS. I know that this way is not for common users but my plugin cannot know if your theme will be using tag ‘div’ with class ‘all_products’ or something like that. WooCommerce use tag ul with class ‘products’, so this is default value in the plugin.
I’d like to have some better solution for this but as for now It is the best I could find.
Regards,
Dima