Can I redo a state without losing my work on the federal return.

[DoninGA]

Yes, you can delete the state return and start the state return from the beginning.  It will not affect the federal return in any way.

See this TurboTax for deleting a state tax return when using the online editions - https://ttlc.intuit.com/turbotax-support/en-us/help-article/state-taxes/delete-state-return-turbotax...