I have two W-2's from same employer for 2 states (CA, AZ). One of these W-2's is mostly blank (Except for State tax information). How should I enter amounts for e-filing?

Enter one W2 for the same employer and then in the state tax section you can "add another row" for additional state information of wages and/or withholding.  Be sure to select the correct 2 letter state code for each.