Ugandan Culture is very different from the West and like in your culture there are accepted things one should do but also there are things that are unacceptable in this culture.
The focus of Ugandans are relationships, family and friends, they come first. Everything else is not as important. Relationship is the first priority.
One of the mistakes often made is dressing wrongly while in the city such as Kampala, Jinja or Entebbe.If you do make a cultural mistake, you will not know so. since most Ugandans will overlook it.
Uganda has a fairly conservative Christian/Muslim based society. It is generally not considered acceptable for women to wear skimpy clothing or to have overt displays of sexuality. The only exception is in certain night life situations in Kampala. Most Ugandans go to church / mosque regularly and consider religion an important part of a moral society. Never criticize religion in presence of a Ugandan!
You will not be taken seriously if you wear shorts outside the obvious tourist destinations and most Ugandan adults would never wear shorts except if playing sport. Use a pair of light trousers to blend in better. Most women wear skirts in rural areas, but trousers are acceptable in cities and larger towns.
A handshake is the most common form of greeting. If your hands are wet or dirty you may offer your wrist instead of hand. Don’t be surprised if you see two men holding hands. This is not a sign of homosexuality which is forbidden by law and is indeed punishable, but rather of friendship.