You cannot file a State return without filing a Federal return (you would file them at the same time), or if filing a State return separate until your Federal return has been accepted. You can file your Federal return now with your DE return, on the Federal return when it asks how you want to pay your taxes owed, choose by check. The you can continue through the e-filing.
When you are ready to pay Federal, you can pay on the IRS website, or mail in a check.
