.
check node version
node -v
check npm version
npm -v
Now if you want to install application on your system globally run below comand.here -g mean it will install globally
npm install -g create-react-app
now if you wan to check globally version install in your system you can use below command
create-react-app --version
now if i want to create react app in my folder make a folder and open command prompt inside the folder and install below command
create-react-app new-app
now to start react app
npm start