How do I download node app?

Could you please guide me on how to download a node app? I'm new to this and would appreciate a step-by-step explanation. Is there a specific version of Node.js I need to install first? Also, are there any prerequisites or configurations I should be aware of before proceeding with the download? Additionally, are there any security considerations I should take into account while downloading and installing a node app? I'd like to ensure I'm doing this safely and efficiently.