You can take demo website as the website you are going to have. Firstly, Experience the entire shopping process as your customer in Demo website, Including Register, Login, Browse products, Add a shopping cart, Set the shipping addresses, Calculate shipping cost, Settle payment etc. And certainly, We are using Paypal Sandbox test account, So you do not have to pay in real.

Secondly, Login Demo websites as a administrator, You can Add/Edit categories, Process orders, Manage customers, Discount promotions, The highest permission to set the Payment Method, Shipping Rate Calculate, and other store-related settings.