I need to cancel my QuickBooks desktop, I have multiple accounts

You tagged this DESKTOP question with ONLINE  - they are different. If you wanted to ask about cancelling one or more of your ONLINE companies then please ask again or be more specific

The only QuickBooks desktop versions that can b canceled are the desktop plus versions and once you do cancel it  (by calling support) you will no longer be able to open that desktop company so be sure to save a local backup first.

To cancel an online (QBO) subscription

Here's how: 

1. Go to the Gear icon and choose Account and Settings.
2. Select Billing & Subscription.
3. In the QuickBooks section, click Cancel.
4. Click Continue to Cancel, then Continue to Cancel again.
5. Answer the short survey, then Click Confirm Cancel.

Also, here's an article that can help you in canceling your QuickBooks Online subscription.