Step 1 : Download node and install https://nodejs.org/en/download/ .
Step 2 : Open Command line for Windows as Administration mode and Terminal for mac/ linux.
Sote :: For mac and linux please add
if the commands in bellow are not works.
Step 3 : Install npm
Step 4 : Initialize react native
npm install -g create-react-native-app
Step 5 : Go to your any project directory and create new project named FirstProject.
Step 6 : Go to your newly created project directory.
Step 7 : Run Project.
Step 8 : For Android Phone . Go to play store and install expo in your android phone.
Step 9 : after start project a QR will be generated on command mode .
Step 10 : Open expo in android/ios phone and scan the QR code.
And That’s All . If you are mac user then there may have the following problem in npm run .