No shop page but only categories and subcategories

As per the default login of WordPress, each entity group should have a base slug. Like category, post, etc.

However, WordPress also let you have your custom permalinks, this will help you further: https://www.wpbeginner.com/wp-tutorials/how-to-create-custom-permalinks-in-wordpress/

If you need further assistance kindly visit WordPress support forum :https://en.forums.wordpress.com/