Naturalism

Good evening!
I don’t understand several points about philosophical naturalism:
1- Naturalism claims that there are no teleological explanations, and if I understand correctly, then the meaning is that there is nothing that works because it was planned in advance for a purpose, but rather it simply exists. And yet it is difficult for me because in the Bible, when a person sets a goal for himself to eat, then the definition is not that there is purposeful planning, but rather that this is the existence of a person, but that a person creates a computer that works according to an algorithm, why is this not said to have a teleological purpose?
2- What does the naturalistic definition add to Aristotle’s words that there is no aspiration to an idea, but that everything exists and nothing else, and this is precisely the naturalistic definition?
3- Naturalists also claim that there is no such thing as supernatural by definition, i.e. that something that is supernatural does not exist. Q. To me, is this essentially a description of a material world in which there is no duality, or is the intention that even if there is a spirit, it can still be explained?
And it’s still not clear to me whether their starting point is that the mind can understand everything? And so how do they align with Kant’s words about rhetoric?
Thank you very much.