How to reconcile a credit card account in Quickbooks Desktop that has never been reconciled before?

1

In an account that has not been reconciled the opening balance is zero.
So your first reconciliation should be done with the opening balance on the statement that was entered in QuickBooks as the closing balance in the reconciliation window.
The reconciliation date should be the start of the statement period.
Also, when you reconcile, see in the reconciliation window that it shows that amount. Then mark it and you’re done.
Now you can start a new reconciliation and carry on the amount from the previous one.