Is there a way to delete the sales tax set up and start over? The set up was done wrong, and I tried correcting it, and it's just worse now

You can deactivate the incorrect sales tax you've made, Sonia32. I'll be glad to provide you with the process to do so.

Please know the ability to delete a sales tax in QuickBooks is currently unavailable. However, you can consider deactivating them to ensure they won't cause any issues with your tax filing. Here are the steps that you can follow:

1. Open your QuickBooks Online account
2. On your left navigation panel, select Sales tax.
3. Select Manage sales tax from your upper right screen.
4. In the Tax agencies tab, identify the tax agency related to the sales tax rate you want to set as inactive.
5. Choose Make inactive in the Actions column beside the rate you want to deactivate. Once the sales tax rate is deactivated, you will see Make active in the Actions column for that rate.
6. Once done, click Done.

For reference here's a screenshot below: 

Moreover, here's an article that you can read for guidance in assigning default tax codes to your chart of accounts in QuickBooks: Set default sales tax code for your Chart of Accounts/
 

The Community forum is always available to help you, Sonia32. Just click the Reply button below so we can help you with your concern.