Make sure you have:
properly set up an environment for React Native (see React Native CLI Quickstart for iOS|Android),
installed MagicScript Command Line Toolkit:
npm install -g magic-script-cli
To create a sample project, type the command below and follow instructions in the wizard.
magic-script init
Remember to select:
cd AwesomeProject
magic-script build ios
or
magic-script build android
This will build the app for the specified platform and will try to run in on a local emulator.