Here are two arguments, following Aristotle, for an Unactualized Actualizer—which can then be shown to necessarily have the other properties of the classical conception of God—but this argument only gets us to a being that is Absolute Actuality.
The first argument is made by philosopher Edward Feser is his Five Proofs of God. This is only the first 14 steps of the proof, which get to the Unactualized Actualizer. Call it a minimal proof of the existence of God.
The second is a my stab at formalizing Feser’s argument, to show that is logically VALID, and any objection to it must be a case that at least one of the premises is FALSE. Let me know your thoughts on it. I’m fairly sure it’s valid.