Let's say you have a file named app.js that contains the following.

console.log("Hello World");

If you use the node CLI to run app.js, "Hello World" should be displayed as stdout on your console.

~]$ node app.js
Hello World

Or, if you have some event that is considered an error, you probably want to use console.error.

console.error("naughty naughty!");

On ES6, you could create a constant that contains the timestamp.

const timestamp = () => `[${new Date().toUTCString()}]`
console.log(timestamp() + " Hello World");

Better yet, use backticks to include constant variables without having to use + or , to break in and out of strings and constant variables.

const timestamp = () => `[${new Date().toUTCString()}]`
console.log(`${timestamp()}  Hello World`);

The console should then contain the timestamp.

~]$ node app.js
[Mon, 08 May 2023 06:51:27 GMT] Hello World

Better yet, use the Winston Logger.

const { createLogger, format, transports } = require('winston');

const logger = createLogger({
  format: format.simple(),
  transports: [
    new transports.Console(),
    new transports.File({ filename: 'all.log' }),
  ],
});

logger.error("my error message");
logger.warn("my warning message");
logger.info("my info message");