How do I get my state income tax return?

You have to file a state income tax return along with your federal income tax return. Both are completely separate, and a refund on one never implies a refund on the other. You state will have a different tax rate than the IRS has, and different tax brackets.

Google your state and filing income tax, like "Delaware state income tax filing". It'll take you to a link where you can file your state return. Most states allow you to file for free so check your state web site before you pay to file. You also have to have completed your Federal tax return because you will need information from that to use in your state return. Have fun :)

by filing a state income tax return