Then, to have a summary of the transaction data, you can run the Profit and Loss by Customer report. Here's how:
Go to the Reports menu.
Scroll down to the Business Overview section and click Profit and Loss by Customer.
You can also customize this report so you can filter to show specific info.
On the other hand, you can also use class tracking, which provides you deeper insights into your sales, expenses, or profitability for each part of your business. To have a better view, take a look at these articles: