Arguments against existence of God.

[Jehanne]

As Professor Edward Tryon speculated long ago, maybe it was due to a quantum fluctuation:

Wikipedia: Edward Tryon -- Is the universe a vacuum fluctuation?

Well according to this speculation, there is no explanation for how a single particle brought about by a "quantum fluctuation" becomes an entire universe.

Also, this theory posits that the universe exists within a plane, a "vacuum". Is that not an example of deductive reasoning?
And is that empty space eternal or did it too have a beginning?
So these theories are pure speculation and they fail to account for existence.
Furthermore, they are based on the assumption that the law of conservation of energy is absolute truth and is a physical law that was always in operation even before the coming into existence of our universe. But all the evidence points to the fact that the energy that constitutes the universe came into existence

Most cosmologists/physicists are of the opinion that the total energy of the Universe is zero:

Wikipedia -- Zero-energy universe

And as Professor Sean Carroll pointed-out in his debate with William Lane Craig, per Professors Stephen Hawking and James Hartle, asking what came "before" the Big Bang may be like going to the South Pole and asking, "Where's south?"  Such may be a meaningless question.

On the other hand, the Universe may simply be eternal, without beginning or end, and without an edge, either, an actual infinite in both time and space.  It seems that you are bothered by the idea of an infinite regress or an actual infinite, but, theism is plagued by these types of paradoxes, also.  After all, if God created the Universe, who created God, and what caused God to create the Cosmos?  Again, this is a very old debate, and while it may be the case that planets move because there are angels pushing them, it is not necessary to believe such, just as it is not necessary to believe in a Creator that caused the Cosmos to come into being.  Maybe the Cosmos just Is.