I recommend these posts:

How did Alexander the Great's campaigns impact Egypt?

What roles would native Egyptians have performed in the Ptolemaic military?

What was the relation like between Ptolemaic Egypt and Rome?

What were some reasons the Ptolemaic dynasty ended?

Did the Ptolemaic dynasty really try to Hellenise or segregate Egypt?

How many Greeks lived in Cleopatra's Egypt and how common was bilingualism?

How accurate is the representation of Egypt in Assassins Creed Prigins?

What positive things did Cleopatra do in her reign?

All of these contain reading recommendations and sources. There are others I can recommend if you elaborate on what interests you about Ptolemaic Egypt.