This is actually a really good question. I have only just started looking into this myself, so my understanding of Ancient Egyptian religion is minimal - but I never let my ignorance get in the way of having an opinion .
Ancient Egypt was a polytheistic world, with a plethora of deities. As far as I can gather, the religion was an evolving one, so as the dynasties passed, the gods changed, developed and even amalgamated.
That said, it is my understanding that Ra (also sometimes called Amun Ra) was known the ‘Father of the gods’ and was the ‘big boss’ if you like. His name also appears in Pharaoh’s title - Pha-RA-oh. He was also known as ‘the sun god’, which is why it was so significant that one of the 10 plagues was 3 days of darkness. Ra, the sun god, was powerless against YHWH. All of the plagues were direct assaults upon the gods of Egypt who were powerless to resist (Exodus 12:12).
In modern times, we tend to think that the Egyptians were really worshipping empty space - there was no substance behind their idols. However, the fact that the magicians were able to replicate (to some degree) the works of YHWH suggests that there were supernatural forces behind the gods. (I find it really interesting that the magicians could copy YHWH’s plagues, but couldn’t reverse or stop them!) Paul writes that those sacrificing to idols are actually sacrificing to demons (1 Corinthians 10:20).
It is also my understanding that Pharaohs considered themselves to be divine and were the ultimate go between for the people and the gods.
They were responsible for ensuring prosperity and plenty for the people. Something that was proved categorically untrue through the plagues.
One last thing I have come across in my limited research (so far) is that the snake was a symbol of power and protection (interesting when you consider what the serpent is in the Bible). You have probably seen Tutenkhamun’s famous mask with the snake head band. So, it was not simply that a staff is long and thin and snakes are long and thin, therefore it made sense to turn Moses’ staff into a snake. It was another direct challenge to Egyptian belief. Moses’ snake ate up the magician’s snakes - showing that their symbol of power and protection would not save them from what was to come.
Like I said, I am just starting out on this area of study, so would love to hear from others and be pointed resources - especially if I’ve been barking up the wrong tree!
I am also really interested to know how you came to discuss this topic with your friend and what their thoughts are and also what you think.