The first revelation of the Qur'an is found in Suratul Alaq.
To understand this, let's look at the context: The prophet Muhammad (peace be upon him) received the first revelation from Allah through the angel Gabriel while he was meditating in the cave of Hira. This momentous event marked the beginning of his prophethood. The angel Gabriel asked Muhammad to "Read!", but Muhammad replied that he could not read. The angel repeated this command three times before revealing the initial verses to Muhammad.
The specific verses that were revealed during this event are contained in the beginning of Suratul Alaq (Chapter 96 of the Qur’an), which means "The Clot" or "The Clinging Substance." The chapter begins with: "Read in the name of your Lord who created – Created man from a clinging substance..." These verses emphasize the importance of knowledge and the idea of learning in the name of the Almighty.
This event marks the beginning of the dissemination of the Qur'an, which would continue for approximately 23 years.