Welcome to the QuickBooks Community, iotw!
I agree with Fiat Lux - Asia about using a sample file. You can find one by clicking the Open a sample file folder in the No Company Open section.

If you need a reference for exporting the sample file to QBO, please check out this article: Move your QuickBooks Desktop file to QuickBooks Online.
If you also want to check the references for QBO, just go to the main support page, scroll down a bit and click More Topics. We also have video tutorials if you need some visual references.
Let me know if you have any other concerns with exporting your data or anything about QuickBooks. Take care and enjoy the rest of the day!