I'm delighted to assist you with this opening balance concern, @danchen313-gmail.
If you want to edit the opening balance of an account in QuickBooks, do it in the Chart of Accounts. Find the Opening Balance Equity journal entry, then change the amounts using the steps below:
Go to the Accounting menu, and select Chart of Accounts.
Locate the account you want to edit then press View register.
Find the entry that has an Opening Balance Equity description in the Payee/Account column, and Opening Balance in the Memo column.
Click on it and start editing the amount.
Press Save, then make sure to read the warning before clicking Yes.
I've got some articles about handling your opening balances in QuickBooks Online: