The capital of Egypt is a chaotic fascinating city difficult to describe in a few words.
During the day you can enjoy the markets and the street sellers everywhere but especially suggested is the bazaar Khan el-Khalili where you can find beautiful marquetry boxes, semi-precious stones, rugs and all kinds of souvenirs.
Of course, you HAVE to bargain. It's part of the culture and the fun for the seller. Try also the tea offered in many of the shops as a courtesy for the customers.
To move across the city, if you are the kind of person who likes to drive relaxed, Cairo is not your place, unless you have previous training from having lived in Mexico City or Tegucigalpa.
Otherwise... strongly recommended to take a cab or the metro service that carries 1,000,000 people daily between Choubra el-Kheima in the north and Helwan in the south. The city is safer than most of the capitals in the world. There are many beautiful and interesting islamic monuments to visit. The admission is not free.
For women it is not necessary to wear a scarf to cover the head or special clothes (as it is commonly believed...) since it is a city where tourists are everywhere. But to enter to the islamic buildings proper clothes are required. That means that neither shorts nor vest tops are allowed and heads have to be covered in all mosques but they provide the necessary items at the entrance.
Very beautiful the mosque Muhammad Ali although is very difficult to choose one in the "city of a thousand minarets”.
A few km.from Cairo you find Gaza Gaza Egypt Border, where the archaeological site with pyramids receives every day thousands of tourists. Obviously, you can't miss that.
At night, Cairo is completely alive. Between the exotic dancers shows and the totally European discos you have a wide offer. But since you can find discos everywhere else, it's best to go for a very "local" one where you can experience the electronic local music which, by the way, is really good.
Shisha and good drinks all over the place.