The built environment description is not a built environment analysis. You are supposed to observe, study, document, and describe the place and the people and things in it. Observe and take notes on what people and things are in the space, what they look like, what the people are doing, what the space looks/sounds/smells/tastes/feels like. In your built environment descriptions, you are trying to describe as best you can what the place is and what you sense when you are there.
In the final project, the built environment analysis, you will be answering bigger questions about the space, e.g., why it is designed the way it is, what effect it has on the people who use it and the community in which it is situated, how it reflects social/political/historical circumstances, etc. That is for later. For now, just document and describe the space.