Download installer here

Select the version for your OS/platforms. If you are using window just press Download for Windows.

Run the installer and follow the installation prompts.

Download installer here

Select the LTS version.

Run the installer and follow the installation prompts.

Test your Nodejs and NPM installation by node -v and npm -v on terminal/command prompt.

After the installation, npm command should works.

Get your GIANT account from person in charge.

Go to the provided GIANT url.

Login to your GIANT account by typing your email and password.