Hello there, edp5-alfred-edu.
If you want to delete the transactions in your register, you can delete each transaction one at a time. Just go to the register and open each transaction and then click Delete.
However, if these transactions are added or matched from the Banking page, you can undo them. Let me show you how:
All transactions will be moved back to the For Review tab and be removed from your register.
On the other hand, if you want to delete the entire data and start over, you can review this link for more details on how to do the process: Delete your data and start over in QuickBooks Online.
I'm just here if you have other questions. Take care and have a great day!