I am trying to add content after the page title and customize the style of page where all products are listed in woocommerce, but I have no idea where is the file that I can copy to my custom theme, I have been able to customize the products in the loop but don't know where to customize this? On inspect element it is the h1 element with a class page-title:
<h1 class="page-title">Nettbutikk</h1>
woocommerce/templates/single-product/title.php is the file you are looking for. You can copy single-product/title.php to yourchildthemefolder/woocommerce/single-product/title.php
Here is a link to their github of that file so you can see it for yourself. Let me know if this helped! :) https://github.com/woocommerce/woocommerce/blob/master/templates/single-product/title.php
To edit the woocommerce product list page, the file woocommerce/archive-product.php needs to be edited.