I have another question, how can I change the /shop / I have tried to change the link of the shop in woocommerce but the /shop never disappears or change.
These margins and paddings are necessary, other pages would be influenced. If you want to remove the gaps on certain pages, send us the pages and your site admin access we shall help to get rid of them.
If you want to change, you need to create another page with URL and title you wish and set it as the shop page in Woocommerce > Settings > Products.