That's like saying we don't know that there is no Superman.
No it isn't, because the question I am responding to it, "Are there no gods or is there at least one?"
If I am asked, "Is there a Superman?" I would answer, "Yes, there is. And back when I was a boy, DC comics actually sued another (Marvel comic, I think) because Superman existed."
Superman is a comic book character with an alter ego of Clark Kent.
Meh.
If asked if the Superman actually exists in reality...I would say, "I doubt it."
I am not stupid enough to say, "No, Superman does not exist."...because then I would put myself into the position of defending an assertion that doesn't have to be made...and is just too goddam hard to defend against someone determined to undermine the defense.
Anyway...either this thing we humans call "the universe" either always has existed in one form or another...or it was created. I do not know which it is...nor do I know the answers to all the questions that guesses cause.
Some people blindly guess there is a GOD. Some people blindly guess there are no gods.
Makes no difference to me...both are just guessing.