How do I only file my Ga tax return?

TurboTax uses info from the Federal return to prepare the state return.   What's the story on your Federal return?   Have you prepared one?   Was it prepared in TurboTax?   If so, was it efiled and accepted?   Or was the Federal return prepared somewhere else?

Even if you already filed your federal tax return, you still have to "prepare" the federal tax return, in TurboTax (TT), in order to prepare and file a state return.  The federal return you prepare in TT, will not actually be filed.  But that will prevent you from e-filing your state return.  It will have to be mailed.