How can I run a report that show both Sales Invoice & Sales Estimates?

I've got steps on how you can run this in QuickBooks Online, leongautots.

In QBO, you can pull up the Transaction List by Customer/Client report. This will give you the information you need. Please note that this is only available for QuickBooks Essentials and Plus version. You can check this article for the report's comparison between QBO subscription for your reference. 

 Here are the steps on how to run the report:

1. From the left panel, select the Reports tab.
2. In the search field, enter Transaction List by Customer/Client.
3. Select the Report period.
4. Click the Run report tab.

Now, you're able to see the transactions both sales invoices and estimates. 

If you need help in customising your reports, you can check it out here for the detailed steps on how to customise it: Customise reports in QuickBooks Online.

Please don't hesitate to tag me in a comment below if you have follow up questions on this. I want to make sure everything is taken care of for you.