Hello there, aredmiston.
The option to run sales reports per customer is unavailable in QuickBooks Self-Employed. You can use the Profit and loss report which summarizes your income and expenses. Then, select the Business Income amount that will route you to the Transactions page. You can export the list to Excel and modify it from there.
You can use these links that will help you in handling QuickBooks Self-Employed:
Let me know if you have other questions. You take care and have a great day!