NPM, NodeJS and PM2 need to be installed.
On First startup, run
npm install
npm run css-build
to install all the neccessary dependencies.
simply run npm run dev to start server and it will automatically restart once you make changes.
Then to start the webserver just run the start.sh, to stop just run the stop.sh
Also you should setup an Apache2 Webserver and Proxy the NodeJS Server to that.
Pug documentation
NodeJS documentation
Express.JS documentation
Bulma Documentation