How should i write a topic sentence on a paragraph about culture

If you are writing a 5 paragraph essay, you should have an introduction paragraphs, three body paragraphs, and a conclusion.  
First decide your topic: culture.  Then choose three topics about culture that you want to cover.  Each of those three topics will have its own body paragraph. In your introduction, you will want to introduce to the reader the fact that you are talking about culture, and then one of your sentences in the intro paragraph will briefly state the topics for each paragraph.  Your conclusion should be very similar to the intro.  The main difference is that instead of introducing the topics you are summarizing what you wrote.  Good luck!