The Website Builder can be accessed through your Project Websites, if you have a currently active Tourney plan on it.
It lets you create a new website from scratch, defining your own theme and layouts, and then combining static content with dynamic information coming from Toornament.
You can switch between a desktop and mobile view for the Builder, to see how your website displays in both configurations, and preview it at any time.
To be able to integrate Toornament data into your website, you need to link one of your tournaments, with a Prime status, with the website (from the Website settings in the Project interface). This is also a mandatory step to be able to publish the website.
The best way to learn how to use it is just to use it, but we have created a dedicated guide category to help you with the builder and its features: Website Builder