Good that I have started with the complicated (see my previous articles on React Native) to find suddenly this wonderful App that seems to me now like a walk on the beach!
I can make it short because all you need is the App for your phone (Android or ios) and the tools for your computer (macOS, Windows (64-bit), and Linux).
Doesn’t this sound like a marvel?
Read through these links and don’t loose any time:
In my case, I had first created a project using the command line tool create-react-native-app
Later I installed the Expo Tools and the phone app. There was no issue at all to get things running smoothly!