How can I remove unwanted invoices appearing in the profit & loss account?

Welcome to the Community, @chiaretto-cn. Let's customize your report so the unwanted invoices will not show anymore. Here's how:

1. From your Profit and Loss Report screen, click Customize.
2. Click the arrow beside Filter, then manually select all the income and expenses that you only want to show on the report under the Distribution Account drop-down. 
3.  Click Run report.

For future reference, you can also memorize reports in QuickBooks Online to easily pull it up when you need them.

Feel free to message again if you have additional concerns. We're always delighted to help.