Hi there, @henry7.
You can start over in QuickBooks Online. I've got some instructions for you on how to handle your last year's balances.
Once you import your data from QuickBooks Desktop to QuickBooks Online, all of your transactions will be transferred. Having that said, I'd suggest moving your list only (vendors, customers, inventory, and chart of accounts) to QuickBooks Online, so you can start over and manage it in your accounting way.
Once done, you can enter the remaining balance from your previous years' transaction and have it recorded as the beginning balance on your QuickBooks Online. This way you can start creating your transactions in the online version.
I've got here some resources that you can refer to about QuickBooks Online and its functionalities:
However, if you need further assistance with the procedure, you can always reach out to our Customer Care Team.
I'll be around to help you out if you have any other questions about this. Just leave a reply below and we'll take it from there. Thanks for coming!