Thanks for posting in the Community, @Donna Bownds. I can help with deleting the ones with zero balances.
Just to clarify, are you referring to deleting accounts that have a zero balance? If so, here's how to do so in QuickBooks Online (QBO).
The following is a brief video to serve as a demonstration:
For additional insight into this process, such as how to restore an account that's been deleted, I suggest the following article: How to delete an account or restore a deleted account.
Should you have meant something else, or need any further assistance, I'll be here. Hope you have a wonderful day.