I noticed a similar question about your inquiry on how to delete the expense or check transaction that was supposed to be a revenue transaction in QBO, Hollysatran. Fortunately, another member of the Community has already posted a reply about it.
I wanted to share a direct link to that conversation where my colleague provided a detailed response: How do I delete an expense/check transaction that should have been a revenue transaction?
Just let us know if there's anything else we can assist you with.