apt update && apt upgrade
apt install nodejs
apt install npm

Or Install Node Manually

cd ~
curl -sL https://deb.nodesource.com/setup_10.x -o nodesource_setup.sh

apt install nodejs

npm i npm -g

Install Yarn

https://yarnpkg.com/lang/en/docs/install/#debian-stable 

npm install pm2@latest -g

Go to Project and

pm2 start server.js
pm2 startup