I'll tell you how you can go to the Print Center inside the return interview where you can choose a PDF to download/print. If TurboTax thinks you were finished, and you don't know how to open the interview back up, my steps below will tell you how.
NOTE: If you have already filed your returns, do NOT make any changes in them when you open your interview back up. If you ever have to prepare an amended return, it has to start off exactly as it was when it was originally filed.
NOTE: Remember all PDF tax documents and tax data files are very sensitive files, since they contain your personal ID info, financial data, and possibly bank account numbers, etc. Be sure to store them safely and securely to guard against computer theft, hacking, etc.