Hi, Then you need to take the shortcode you are using out of the page or post it should be one of the following:
[wp_eStore_cart] Display the shopping cart on a post or page
[wp_eStore_cart_when_not_empty] Display the shopping cart on a post or page but the
cart is visible only when there are items in the cart
Then you will need to check the “Automatic redirection to checkout page” checkbox in the main settings page of the eStore and specify a check out page URL in the “Checkout Page” field.