Note: Make sure you have completed the React Native - Environment Setup instructions till "Creating a new application" step, before proceeding.
# using npm
npm install
# OR using Yarn
yarn install
cd ios/
pod install
Let Metro Bundler run in its own terminal. Open a new terminal from the root of your React Native project. Run the following command to start your Android or iOS app:
# using npm
npm run android
# OR using Yarn
yarn android
# using npm
npm run ios
# OR using Yarn
yarn ios
If everything is set up correctly, you should see your new app running in your Android Emulator or iOS Simulator shortly provided you have set up your emulator/simulator correctly.
This is one way to run your app — you can also run it directly from within Android Studio and Xcode respectively.