I entered a Recovery Rebate Credit of $2,400. We had received stimulus monies, should I have entered $0. Do I need to amend my tax return?

No do not amend for this.    Many people have made similar mistakes.   The IRS is cross checking when you enter an amount for the recovery rebate credit on line 30.  They will see that you already received stimulus money and reduce your refund.   This will delay the processing of your tax return, so do not expect a quick refund.

Thank you for your quick response. I was on the fence about amending the Federal return since it had been accepted in early March. I hope if I now owe that we are not penalized because of this error.