I would learn React if I was you. Check out create-react-app on Github. It will set you up with a working app to play with in a matter of seconds. If you're expecting to use React Native it looks like they have a create-react-native-app also.
I got my android app running which was easy after all the installs and updates.
Now I'm doing some weird command line stuff to try to get my Javascript server to wake up. Changing ports, more SDK updates, etc... Changing my App.js doesnt update, except if I turn everything off and back on again.