Hello,
Sorry for the inconvenience but as you know the default layout of the checkout page comes from WooCommerce end and isn’t directly editable because WooCommerce doesn’t allow it to do so.
But under the WoodMart Theme, using the Theme’s Layout Builder you can create Custom Layouts for WooCommerce pages like Shop, Category, Single Product page, Cart, and Checkouts. So, you can use that to create your own custom layouts for these pages.
Further, you can read more about the Layout Builder here: https://xtemos.com/docs-topic/woodmart-woocommerce-layout-builder/
Hope this helps !
Best Regards.