What is the proof of the validity of the Islamic religion, what new did it bring, and how does the religion answer the question, "Who created God?"

The cosmic proofs that Allah is the Creator are four: the existence of creation, the perfection (mastery of creation), the predestination (creating everything with measure and proportion), and the guidance (guiding the creature to what benefits it).

As for the question "Who created Allah?", it is logically impossible, because the Creator cannot be created. To get rid of this whisper, it is recommended to seek refuge in Allah and stop, or to say "Allah is One, Allah is the Self-Sufficient Master, He begets not, nor is He begotten, and there is none co-equal or comparable to Him," and to spit dryly to the left three times, or to say "I believe in Allah and His messengers."