execute the start script with Nodemon

in your dir
add git init
npm init

then add your info about what you need
and press enter

now we have *package.json
*
go to part of scripts

and add your starter file
my starter file is app.js

  "scripts": {
    "start": "node app.js",
    "dev": "nodemon app.js"
  }

Then you can use command:

npm run dev