ES6 is just a JavaScript today and you don't need to do anything to init it. All tutorials you see today, of course, are written in modern language and you may and have to write the same way today. ES6 is supported by any modern browser, however, it is still recommended to transpile ES6 into older ES5 and only if you need to support older platforms.

To do so you can use Assets Builder which gives you all tools you need for modern web development out of the box. Just node build js and it works.

If you will need any support, please feel free to ask on our Gitter channel.

If you need ES6 server-side, then you can use it with latest Node version without transpilation, however, you still have to use require() syntax instead of import/export.

In the tutorial they are most likely using the latest version of Node JS, which allows you to write ES6 (without ES6 modules). There's no need to configure anything for that.

If you have the same question about javascript that needs to be executed in the browser, then you'll need a build tool that transpiles ES6 to ES5. There are many tutorials out there that explain you how to do this. An example would be the following link: ccoenraets.github.io/es6-tutorial/setup-babel.