Go through each of the separate lessons. They are all in German because that is the lesson I am studying. They are kind of random sentences, and they are by no means for a complete beginner! There is sound!
I tried to model as close as I could the actual Duolingo platform. I did this project for Camp Duo (https://blog.duolingo.com/camp-duo-2020-language-learning-in-your-own-backyard/), and I though it would be fun to do it on Scratch! Enjoy! Also, the sentence recording in the second exercise is actually one of Duolingo's sentences. If you aren't learning German or just can't tell what the voice exercise is, it's "Wer steht im Regen?" (literally Who stands in the rain?)