As for doing your 2017 return, you can do it with TurboTax, but you will have to use the desktop software that you will download to your computer - the Online system is only for the current tax year (2019).
For instructions on how to do this, please see this TurboTax FAQ on how to file a prior year return.
If you did not do your 2017 federal return in TurboTax, you will have to enter all your federal data and then do the state returns.