Nairobi
I stayed with a host family, which if you are going with a program, is the best option to get you culturally integrated. On the first day, we went into the city center to the traditional Kenyan market. My host sister was able to help us barter in swahili, but everyone speaks English mostly as well. We shopped traditional Kenyan clothing, jewelry, art, and more. After this, we went to walk around the Kibera slums (the poorest slum in Nairobi) and talked to the local people. There are additional artisanal markets that the locals stand up to sell homemade shoes, clothing, jewelry, food, etc. While there, we really wanted to help out the local businesses and people, so we spent a lot of time talking to and supporting the very small businesses that they had.
We had gone to a nearby mall, which was very westernized and only accessible to "rich" people, and purchased essentials that some people who lived in the slums might need. Due to the fact that it is so insanely cheap in Kenya, it was fulfilling to be able to give these people so many things that they had never had before.
For dinner, we went to a local Kenyan restaurant and had Ugali - a traditional Kenyan dish that's eaten with your hands. Its delicious and simple! After dinner, we went to a local hookah bar, and out to a couple clubs after that. I would ONLY go out at night if you are with a local group that knows the cities and language, as it can be dangerous to do so by yourself. The clubs are extremely fun and a little wild, so if you are going out, make sure you are extremely safe.