The first part could be something like "The USA is such a big country and there are so many places to see, things to explore and foods to eat."
Then you could talk about how people move to America from many different countries and so we have a lot of different things influencing our culture. There are many Mexicans and people from Latin America who move there and so we have a lot of Mexican foods everywhere, at restaurants and also at home. But we also still have the traditional hamburgers and French fries. We had many Italians move there too, which is how pizza and pasta got so popular.
We had many Jewish people move to America and this is one of the reasons the movie industry in Hollywood got so big. The Jewish culture is known for its writers and many Jewish Americans went to California to write for the movies and build Hollywood in the first half of the 20th century (1900-1950), and they are still a very big part of the movies today.