I am the girlfriend of a man who is divorced with child. He says he signed away his rights in the divorce but child support was still sought after. We have a bank account with both our names on it but since he is unemployed at the moment all the funds in such account we placed by my direct deposits. A court order was placed to have all income garnished and they wiped out my account of everything but $14.00. Is this justifiable? Am I obligated also since we are dating not married? Or is there a way that I can appeal the garnishment?

You can appeal it and you will have to prove how much of it was your money. By having a joint acount it can be garnished for funds.

Rights can not be "signed over" in a divorce, the other parent may have gotten primary or full custody both physical and legal. But that is not signing over his rights, it just means he does not have any of the rights at this time, but has the ability to file for visits latter if he wanted them.
OR he signed some fake paper his ex had that fooled him.

But yes he owes child support and I would even say I personally think he is lying to you and can't provide any proof of this signing away. He knows he owed it since they would have tried to collect before the garnish. I could be wrong of course, but my opinion

If you have mixed funds, you can file for your money back after proving it was your money to the court