In this video, we start off with a blank React Native project and walk through how to add TypeScript and compile the code down to JavaScript that will then run in your app.

http://reactnative.training/

https://github.com/react-native-training/modern-react-native-typescript-boilerplate

https://medium.com/react-native-training/up-and-running-with-react-native-and-typescript-8d398e910a19