I got you covered, moniqueh1905-gma.
To delete transactions such as invoices or expenses in your QuickBooks Online account, you can follow these steps:
For other transactions like sales receipt, quotes, or bills, you will have to open them one at a time then delete. Here's a link for reference: Void or delete transactions in QuickBooks Online.
If you want to delete everything and start over, you can reset your account within 90 days of signup. Please take note that the process is permanent. This is for QuickBooks Online Plus, Essentials, or Simple Start users only.
Note: If you're using the Accountant version of QuickBooks Online, don't follow this process for your own firm’s books. It could cause irreversible damage.
Warning: This process will delete all data in the company file. Once you delete, you can’t restore it.
Things to know:
Once complete, you will be routed back to your homepage.
On the other hand, if the account is more than 90 days, you can follow the steps above or cancel the subscription. I've got this article for the steps: Cancel your QuickBooks Online subscription.
Please let me know if there's anything else you need. I'll be around to help you out again. Stay safe!