What was Egyptian culture like before egypt was united in 3100 BC?
In prehistoric Egypt, their agriculture started to begin. By around 5400 BC, the people in northern (Lower) Egypt were farming, while the people in southern (Upper) Egypt were still engaged in pastoralism (ie. the herding of sheep and goats). They were already starting their burial customs that were known in later Egypt; in this case, it was burying precious objects with the dead. The Nile Valley didn't see permanent settlements using agriculture until after 4000 BC.
For the Naqada periods (I: 3800-3550; II: 3550-3200; and III: 3200-2900), we mostly get our evidence from cemeteries. They also show the beginnings of later Egyptian burial practices by burying the dead facing west and leaving gifts with them. Naqada II gives us the first instance of wrapping a body in linen, which turns into full mummification later. Wealth and status was indicated by whether they were buried in a tomb (they were the precursor to the far more elaborate ones later, including the pyramids) or a shallow pit, and what was left with them when they were buried (poorer people only had pots, while richer people had things like mace heads and carved palettes). By 3400 BC, every aspect of the later Egyptian culture was in existence to some degree: farmers relying on the Nile, settlements in the valley, and burial practices. The most prominent settlements were at Naqada, Hierakonpolis, and Abydos.
During Dynasty 0 (3200-3000), there were human sacrifices when kings were buried (namely their servants to serve them in the afterlife, and dwarves on occasion to entertain them), but that didn't survive past the 1st Dynasty. King Scorpion and King Narmer were a part of Dynasty 0.
Basically: the culture in Egypt before the unification was simply the beginnings of the culture of Egypt after the unification: agriculture, burial practices (facing west, buried with material goods, from shallow pits to larger tombs, from burying in regular clothes to wrapping in linen).