How do i save a PDF file of my fed and state return?

You can still go back and save your return after the filing.  Follow the steps below (these steps are for online users) -

• Log into your account
  
• Hit the Taxes tab and select My Tax Timeline in the dropdown menu
  
• You should see your Federal and State returns and their statuses
  
• Scroll down towards the bottom until you reach the section Some Other Things You Can Do
  
• You will have three options that are relevant to saving/printing your return, I would do all three just to be safe:
  
• Choose Download / Print Return (pdf):  This saves a copy of the pdf of your return that includes all forms required for filing.  You can print if you wish or just save the pdf to your computer.
  
• Choose Download All Forms and Worksheets:  This saves a more expansive copy of your return that includes all the forms and worksheets TurboTax used to compute your return even if they aren't sent to the IRS (this can be 100+pages so don't print it unless really want to)
  
• Choose Save .taxfile:  The .taxfile is the TurboTax extension of your tax file.  It is required to open your return if you ever needed to use the desktop program to amend your return in later years, so it is good to keep a copy of this just in case (though you won't be able to open it without TurboTax software installed on your computer)