Why is npm start error creating react app

I'm learning reactjs I started with installing nodejs and then ran these commands inside my project folder "React"

'''npx create-react-app hello-world cd hello-world npm start'''

but then instead of going to the browser i receive error:

npm ERR! missing script: start

npm ERR! A complete log of this run can be found in: npm ERR! C:\Users\abc\AppData\Roaming\npm-cache_logs\2020-02-21T13_34_26_640Z-debug.log

PACKAGE.JSON CODE:

{ "name": "hello-world", "version": "0.1.0", "private": true, "dependencies": { "react": "^16.12.0", "react-dom": "^16.12.0", "react-scripts": "3.4.0" } }

Help me solve this error i dont want it to demotivate me from learning React