Problem with JavaScript in node

I am having trouble with the JavaScript in node video. My understanding is I should insert the file js-basics (created on the desktop) and then type $node index.js, to link with the file created on Visual studio code. When I insert the file and then type $node index.js, it states ‘not recognized as an internal or external demand’. Please any help will be greatly appreciated, I’ve done the first course and had trouble with this first time round and I am still having trouble with it now. Btw I’m using windows not mac.
Thank you,

In your system node is not installed properly or Environment Variables are not set up.
You can check this by opening command prompt in that write node -v
First Install node from Node.js.