After you file

I've tried to follow your instructions and still am not getting too far along.  I open TurboTax (empty file), choose amend a filed return, but never get an opportunity to open my original return as a starting point.  I am able to find form 1040-x but again it is blank and looking for the original information but I can't figure out how to load in the original return.  I am working on a Mac.  Any suggestions?