Joseph’s brothers sold him as a slave and he ended up in Egypt. Joseph’s father and brothers all eventually came to Egypt because of a famine. Some 210 years later Moses, with the help of G-d, led the Jewish people out of Egypt.
There was a Jewish presence around Cairo for over 2000 years going back to pre-Temple times. Before 1948 there were about 70,000 Jews. Most Jews left for Israel after it became an independent state. Then, following the 1967 war where Egypt suffered a major blow from Israel, the remaining Jews were pretty much thrown out of Egypt.
Today there remain fewer than 100 Jews living in Egypt.
During the time of Alexander the Great, the Ben Ezra Synagogue was built. It was home to hundreds of thousands of ancient Jewish documents and texts, of which the majority have been relocated to Cambridge, England.
Over the last couple decades there have been a few Jewish organizations working on getting Jewish relics out of Islamic countries by way of smuggling, bribing, and or buying. Thus, Jewish relics in Islamic countries have largely disappeared. If there is, say, an old Torah scroll in an Islamic country, chances are there is a Jewish organization trying to get it out.
As far as Jewish sites go, if you believe that the Jewish people built the Pyramids when they were slaves to Pharaoh, then the pyramids are an interesting attraction to see. And if don’t believe that the Jews build the pyramids, than the pyramids are still a great attraction to see.
There are around 10 synagogues in Cairo and a further 10 synagogues in Alexandria, some newer and some older. Access to some may be difficult. If you are serious about visiting any synagogue in Egypt, do some research online before you go to see what the current situation is.