On your W-2, section 10b should be asking for the state ID #. If you do not have the state ID # on the W2, then leave it blank.
You should be able to get past that field being blank and continue on with the return.
Are you asking about a W-2 or a 1099G for unemployment? If it is from one of the states that does not have a state income tax, leave it blank
(On a W-2, box 15 is for the state ID)