While watching this video, think about what you know of the Roaring 20's, and how The Lost Generation shows a different side of the 1920's.
https://www.britannica.com/topic/Lost-Generation
This source should provide a lot of general information about the "who" and "what" of the Lost Generation.
https://www.thoughtco.com/the-lost-generation-4159302
While reading the article, pay special attention to who the Lost Generation was and why they were called that.