The Sign In/Sign Up page, which is shown below, also allows the customer to create a new Google Account or log in to an existing account.

Google will display the Place Order page
This page, which is shown below, lists the items in the customer's order and the shipping options available for the order. The Shipping Information and Tax Setup pages explains how to configure your shipping options and tax rates. The Place Order page also lets the customer choose the shipping address for the order and the credit card to charge for the order. In addition, the Place Order page allows the customer to choose whether to share her email address with you or receive promotional email from you.

Buyer can refer to Purchase History page to track the status of the order.
The Purchase History page displays a link below the order history that allows the buyer to contact you with a question about the order. For example, the buyer could ask to change the shipping address for the order or to request a refund for the order. Google will then send you an email with the buyer's question. If the buyer requests a refund, Google does not automatically process a refund or cancel the buyer's order. Google just forwards the request from the buyer and you can issue a refund or cancel the order in the Merchant Center.