Cleopatra wasnt an egyptian, she was a greek macedonian. Egypt was ruled by the Ptolemy dynasty(greek macedonian) and was infamously isolated and incestuous. Their court was mostly greeks or hellenized(greekified) egyptians/jews. In fact, Cleopatra was the first Ptolemy to even bother to learn egyptian, in 200 years of their rule.

Also egyptians arent black, even today they have all kinds of skin colours. Primarily they fucked other mediterranean people, greeks, carthaginians, romans, phoenicians, hittites. Most black people live(lived) below the Sahara desert, so while there was some trade traffic towards/from that direction, it was pretty limited in comparison. You did have things like the kingdom of Kush but for the most part Egypt had more to do with mediterranean(and middle east) states than with subsaharan ones.