Short answers, pulled from the story.
The Nile has been the lifeline for Egyptian culture since nomadic hunter-gatherers began living along it during the Pleistocene. Traces of these early people appear in the form of artefacts and rock carvings along the terraces of the Nile and in the oases.
Archaeological findings support the view that Narmer, the final king of the Naqada III period, was the first ruler to claim to have united the two lands around 3150 BC. His name is known primarily from the famous Narmer Palette whose scenes have been interpreted as the act of uniting Upper and Lower Egypt.
Djoser of the Third Dynasty ordered the construction of the first pyramid called the Pyramid of Djoser in Memphis necropolis of Saqqara. Sneferu the dynasty founder is believed to have commissioned at least three pyramids while his son Khufu erected the Great Pyramid of Giza.
The Hyksos first appeared in Egypt c. 1650 BC when they took control of Avaris and rapidly moved south to Memphis. This event occurred during the Second Intermediate Period which marks a time when Egypt once again fell into disarray between the end of the Middle Kingdom and the start of the New Kingdom.
Alexander III of Macedon conquered Egypt in 332 BC with little resistance from the Persians. He visited Memphis went on a pilgrimage to the oracle of Amun at the Siwa Oasis and founded a new Greek city Alexandria to be the new capital.