You lost me at

  yarn add native-base --save
  
  npm install @expo/vector-icons --save

When I read `native-base` I was all: ewww. Everybody I talk to who used it in previous project regretted it and build back.

Second, the mixture of yarn and npm in the code snippet shows that the author either didn't understand what they are doing, or does not care to lead with a clean example. It's okay to stick with only npm in a beginners tutorial.

Update: Also, why the Python prerequisite?