What is the evidence that Allah Almighty is the Creator of this universe, and not another god?

This doubt is from the whispers of Satan. The polytheists themselves acknowledged that Allah is the Creator, as He states: {And if you asked them, "Who created the heavens and the earth and subjected the sun and the moon?" they would surely say, "Allah."} [Al-Ankabut:61].

The Quran questioned, disapprovingly: {Is there any creator other than Allah who provides for you from the heaven and earth?} [Fatir:3]. What then is the answer for one who doubts His creatorship? There is no rational ambiguity regarding the existence of another creator, for Allah the Almighty says: {Had there been within them [i.e., the heavens and earth] gods besides Allah, they both would have been ruined.} [Al-Anbiya:22]. This demonstrates the impossibility of Allah having a partner. And if we were to assume the existence of gods, each god would have taken what it created, and some would have ascended over others, leading to corruption. For gods are either equal, which is a repetition without justification, or they differ in attributes, in which case the one with imperfections is not fit to be a god.

Seek refuge with Allah and recall the saying of the messengers: {Is there any doubt concerning Allah, Creator of the heavens and the earth?} [Ibrahim:10]. Address doubts by seeking refuge in Allah, frequently repeating "La ilaha illa Allah" (There is no god but Allah), accompanying righteous people, seeking knowledge, and reading books specifically dedicated to this matter.