The cart template is used to control the layout of the view cart page.
You will want to include, at least, the following shortcodes.
[pb_cart_table] – This will display the actual table listing the contents of the cart.
[pb_cart_continue] – Continue shopping button that takes the client back to their gallery.
[pb_cart_checkout] – Continue on to the checkout page where your client can enter their information for checkout.