If you already paid for the state return, you cannot completely delete it, but even if you already paid for it, you should still be able to start over with the state return by using the steps in the FAQ below. Read the whole FAQ first to see which one describes your situation.
FAQ: How do I delete my state return in Online TurboTax?
https://ttlc.intuit.com/turbotax-support/en-us/help-article/state-taxes/delete-state-return-turbotax...
