[WORDPRESS] Customize the code of form-login.php WooCommerce template via your active theme

WooCommerce template files contain the markup and template structure for frontend and HTML emails of your store. When you open these files, you will notice they all contain hooks that allow you to add/move content without needing to edit template files themselves. This method protects against upgrade issues, as the template files can be left completely untouched. Template files can be found within the /woocommerce/templates/ directory.

You will need to copy from woocommerce plugin folder, a subfolder named templates to your active child theme (or theme) and to rename it woocommerce. After that you find inside that new woocommerce folder in checkout subfolder a template named form-login.php

More info here:

https://wordpress.stackexchange.com/questions/193435/woocommerce-registration-page

https://stackoverflow.com/questions/23821488/separate-registration-page-in-woocommerce-website

https://stackoverflow.com/questions/39708872/customizing-checkout-form-login-php-template-does-not-display-button-text

https://docs.woocommerce.com/document/template-structure/

Put a custom field https://usersinsights.com/woocommerce-custom-fields-registration/

and if you want customize standard Wordpress Login

https://themetrust.com/build-custom-wordpress-login-page/