Clone this repository then run yarn install from the root of this repository to automatically install the necessary dependencies, which you can also inspect from the package.json file. Configure Expo and login to your account if you haven't. Then run yarn start to start the development server. Your default browser should launch and display a QR code.
Install the Expo client app on your iOS / Android device. Scan the QR code and the app should launch on your device. Any changes you make to the code will now be reflected on your locally hosted version of the app.