To build your site run the NPM build script from the project root:
npm run build
Your static site will be generated in the /dist directory.
To preview a built site using PHP you can use PHPs built-in web server:
php -S localhost:8000 -t dist
To preview changes as you build your site run the NPM watch script:
npm run watch
This script uses Browsersync to run a development server at http://localhost:3000 where any changes you make will be reflected in the browser.