You must be using "Classic" customer accounts for your store to use this template. To learn more about the difference between Shopify's "New" and "Classic" customer accounts, take a look at their Customer accounts documentation.
The page for a singular order has all the details about the order including a breakdown of the cost. It's referred to in the Customer account/Orders page as an "Invoice". It looks like this:
This template works like other templates where you can also add other sections to the page.