How do I download this?

[IAmNewToGitHub12]

Do I download from the source zip? or do I need to use coding to download it? I am confused (Edit: I downloaded it but when I try to put in a ROM it says something about invalid plugins, and when I go to a plugins setting it crashes.

[Jj0YzL5nvJ]

This is an example of how mupen64plus is used (custom script + commands).

If you don't want to do any of that, just use RMG.