The relevant conception you are looking for is “Buddha Nature.” But the Buddha himself didn’t answer questions like yours, seeing no profit in them.
Aristotle’s “first mover” was a necessary logical outcome of his assumption that there was a state other than motion, leading him to see that he then needed an explanatory device to put things in motion. Buddha Nature is not that. It’s not an explanatory device created to ‘wrap things up’. It’s not the result of speculation.
As Parmenides pointed out before Aristotle’s time, talk about nonexistence and nonexistent things is empty of meaning. Aristotle began with an incorrect assumption and then found himself painted into a corner. So he gave that necessary logical device a name “First Mover” (which he acknowledged was like “God”), and ‘solved’ his problem. This was the kind of outcome the Buddha suggested was a feature of such speculation.
Buddha Nature is the closest to what you are looking for. I prefer “naturing” myself because “nature” is a noun in English, and thus names an independent self-existing thing or idea about them, and the Buddha pointed out that there are no independent self-existing things, which is something you can verify yourself through meditation practices. The word in Buddhism is “Dharmata” (not to be confused with “Dharmadatu”), and is better understood as “naturing”.
If you’re interested, I have written more on this specific question in an article: “A First Mover Is Not Needed” it might reset your thinking about this.