Can I void or delete a wrong journal entry?

Hi there, 

Glad to have you join the Community. I'll be glad to give you a hand with reversing/deleting a journal entry in question using QuickBooks. 

The program provides both options of deleting and reversing. Reversing a journal entry simply reverses the debits and credits and it doesn't delete the original journal entry. Whereas, deleting the entry will completely erase it affecting your account totals. For more in-depth info on how to either delete or reverse a journal entry, please check out the following article that shows you how to: Reverse or delete a journal entry in QuickBooks Online. 

Let me know if this info helps. I'll be here in case you need further assistance.