The Cobra was a representation of Wadjet-the patron goddess of Lower Egypt (which was actually in the north, but was called Lower because it was downstream).
The Vulture was a representation of Nekhbet, the patron goddess of Upper Egypt (which was in the south, but was up river).
Together, they were called Uraeus.
The two were warring kingdoms, united under king Meni (Menes in Greek). Later, you would see the king wearing both the White Crown of Upper Egypt and the Red Crown of Lower Egypt-the same goes for their respective Godesses, Wadjet and Nekhbet.
As for his layers of necklaces-if you look carefully at his shoulders, you’ll see that they are covered by the head of the falcon god, Horus-and his wings meet up and cover his chest-if you look closely, you’ll see that they resemble feathers.
His beard was ceremonial, and the sign of a pharaoh-this was used regardless of gender, as Hatshepsut, a female Pharaoh, would also be seen wearing one. Worn during ceremonies-it was made of goat hair.
The Headress, called a Nemes-is typical throughout Egyptian history-though none have ever been found in any tomb-due likely to the fact that like crowns in Europe-they were signs of kingship and were passed down and eventually lost or stolen.
Hope I was helpful.