Is Achilles’ story true? What is Achilles’ weak point?

In the twelfth century BC, the world was witnessing many changes and the rise of many countries, the most famous of which is ancient Egypt and also the civilization of the Hittites in the country of Phoenicia and Syria, but the country of Greece in this period has united in the hands of one man, which is Agamemnon, the king, who wanted to rule the whole of Greece, and only the city of Troy remained in front of him, famous for its magnitude and strength of its fortresses, for this reason Agamemnon invited both Hector and Paris, sons of the King of Troy, to talk about the city’s accession to the dependency of Greece, Agamemnon then prepared his armies for the Hittite war, but a big surprise occurred.

What is the story of Achilles?