I down loaded a pdf just for a review and TT now tells me I completed my return for 2016. That is not the case. How do I continue working on my 2016 return.?

When you sign onto to your online account using the exact same user ID you used to create the 2016 tax return you will land on the Welcome Home screen.  Click on My TurboTax at the top left of the program screen.  This will take you to the 2016 Timeline.  Under the section Some things you can do:  Click on Add a state (you will not actually be adding a state).  This will take you to the 2016 online tax return.