Why does my return keep getting rejected and saying it's a duplicate when it was never accepted in the first place?

Did your parents file their tax return and have you as a dependent on their tax return?  If so, this would get your e-filed return rejected for duplicate Social Security numbers.

Could your parents, or someone else, have filed a tax return for you? It's also possible that, without realizing it, you did something in TurboTax that resulted in the return being e-filed. For example, people sometimes accidentally file the return when they meant to file an extension.

What is the exact reject code and message that you are getting? If it's R0000-194, it's not because of being claimed as a dependent. It means that a tax return has already been filed with your Social Security number as the taxpayer. This could be one of the possibilities that I mentioned above, or it could be identity theft.