Thank you for posting here in the Community, @office-moonautom. And I can definitely help you start over with new books in QuickBooks Online (QBO).
Since you're using your QBO for years now and want to start from scratch, you can cancel your current account and start a new company with the same user ID and password you used before. Let me guide you how.
First off, let's cancel your current account. Here's how:
Then, you can now Sign up for QuickBooks Online using the same user ID and password to start a new company.
I'm adding this article for more details: Delete your data and start over in QuickBooks Online.
Please know that I'm just a reply away if you need any further assistance with QuickBooks. Wishing you and your business success.