Now that you can see the direct relationship between people, things, pronouns, and definite articles, it's time to branch out one step further to the indefinite articles.
If you haven't yet, you'll begin to see even more in this lesson why it's imperative that you work to get a handle on which nouns belong to which der/die/das/die grouping, because that is foundational information for your German learning.
Review the transcript, study the lesson and do the quizzes: www.newsinslowgerman.com/series/guts/11/transcript