If you want to edit archive page (Shop or Blog) using Elementor you need to use Elementor Pro, the default Elementor does not have such an option.
Go to Theme Options > WooCommerce > Shop and check available settings.
About the Checkout page, by default, it comes from WooCommerce and contains only 1 shortcode – https://woocommerce.com/document/woocommerce-pages/ You can edit Layout via Theme Options > WooCommerce > Cart/Checkout layout.
Regards