in the current directory do
react-native -v
you will get the following
react-native -v react-native-cli: version react-native: version
if it shows command not found the n you have not installed react native in the directory. Do a npm init in new folder and try installing a new react native project there by doing npm install -g react-native-cli
Follow the steps to add path variable react-native.
You’re good to go.