There were at least three separate cosmogenies in Egyptian mythology, corresponding to at least two separate groups of worshippers.
1. The Ennead, in which Atum arose from the primordial waters
(Neith),
and masturbated to relieve his loneliness. His semen and breath became
Tefnut (moisture)
and
Shu (dryness),
respectively. From Shu and Tefnut, were born
Geb (earth)
, and
Nut (sky),
who were born in a state of permanent copulation. Shu separated them, and their children were Ausare (Osiris; death), Set (desert), Aset (Isis; life), and Nebet Het (Nephthys; fertile land). Osiris and Isis were a couple, as were Nepthys and Set.
2. The Ogdoad, in which Ra arose, either in an egg, or a blue lotus, as a result of the creative interaction between the primordial forces of
Nu/Naunet (water)
, Amun/Amunet (air),
Kuk/Kauket (darkness)
, and Huh/Hauhet (eternity). Ra then created Hathor, his wife, with whom they had a son, Hor (Horus; in the form known as Horus the Elder), who was married to Isis. This cosmogony also includes Anupu (Anubis) as lord of the dead, amongst others.
Over time, the rival groups gradually merged, Ra and Atum were identified as the same god, making Atum's mysterious creation actually due to the Ogdoad, and Ra having the children Shu and Tefnut, etc. In consequence, Anubis was identified as a son of Osiris, as was Horus. Amun's role was later thought much greater, and for a time, he became chief god, although he eventually became considered a manifestation of Ra.
For a time, Ra and Horus were identified as one another, and when the Aten monotheism was unsuccessfully introduced, it was Ra-Horus who was thought of as the Aten, and the consequent cosmogony this inspired. Later, Osiris' cult became more popular, and he became the main god, being identified as a form of Ptah. Eventually, all the gods were thought of as aspects of Osiris, Isis, Horus, or Set (who was by now a villain), indeed, Horus and Osiris had started to become thought of as the same god. Ptah eventually was identified as Osiris.
Creation Myth 3
In the beginning, before there was any land of Egypt, all was darkness, and there was nothing but a great waste of water called Nun. The power of Nun was such that there arose out of the darkness a great shining egg, and this was Re. He was all-powerful, and he could take many forms. His power and the secret of it lay in his hidden name; but if he spoke other names, that which he named came into being.
"I am
Khepera
at the dawn, and Re at noon, and Tem in the evening," he said. And the sun rose and passed across the sky and set for the first time.
Then he named Shu, and the first winds blew; he named Tefnut the spitter, and the first rain fell. Next he named Geb, and the earth came into being; he named the goddess Nut, and she was the sky arched over the earth with her feet on one horizon and her hands on the other; he named Hapi, and the great River Nile flowed through Egypt and made it fruitful.
After this Re named all things that are upon the earth, and they grew. Last of all he named mankind, and there were men and women in the land of Egypt.
Then Re took on the shape of a man and became the first Pharaoh, ruling over the whole country for thousands and thousands of years, and giving such harvests that for ever afterwards the Egyptians spoke of the good things "which happened in the time of Re".