Always refer to:
npm init <initializer>
npm init -y
npm install
node app.js
https://nodejs.org/en/docs/
https://www.npmjs.com
npm install chalk@2.4.1
>> This will install this particular version. Information will be added to your package.json, so whenever you use 'npm install' it is fetched again.
npm i nodemon -g
>> This will install the package globally on your operating system, note that your 'package.json' won't be changed