How do I retrieve my 2016 and 2017 tax returns if I purchased plus benefits those years ? I’m unable to go back and view them. Just wants me to file for this year saying I’m already 50% comp

To access your current or prior year online tax returns sign onto the TurboTax website with the userID you used to create the account - https://myturbotax.intuit.com/

Scroll down to the bottom of the screen and on the section Your tax returns & documents click on Show.  Click on the Year and Click on Download/print return (PDF)