Install dependencies

npm install
npm install --only=dev

Setup Laravel Mix to your needs

Normal behaviour:

Images: Copy from assets/src/images to assets/dist/images
Fonts: Copy from assets/src/fonts to assets/dist/fonts
JS: Compile assets/src/scripts/main.js
JS: Merge to single file assets/src/pages/*.js
CSS: Compile Sass assets/src/styles/main.sass

More Configuration

See webpack.mix.js file OR https://laravel.com/docs/5.5/mix