1-Open your terminal
2-To install node.js, use command:
sudo apt install nodejs
       
3-Once installed, verify it by checking the version using command:
node -v or node –version

It is recommended to install Node Package Manager(NPM) with Node.js.
NPM is an open source library of Node.js packages.
To install NPM, use commands:

sudo apt install npm
npm -v or npm –version