I don't have a dick to give - You wanna give advice but you don’t know what you’re talking

You wanna give advice but you don’t know what you’re talking about. You’re like a dog who thinks he’s a detective.

I don’t have a dick to give, I just have a dog’s opinion.

I don’t have a dick to give, I just have a guess.

I don’t have a dick to give, I just have a theory.