Ok great so literally the two guys I started watching are the wrong ones. of course. Also, very curious why CommonProxy and IHasModel are bad practice (other than the Hungarian notation there). That is straight from loremaster, and wondering why this is bad practice. Nevermind, I kept reading. Although from a design patterns perspective I very much agree with a HasModel Interface. And very much disagree with using a CommonProxy lol. You can separate and declutter your main file in much better ways that breaking the purpose of a structure.
I am new to mc modding as well. (as of today) I am a professional developer, and want to get my younger brother into coding as well, and I thought a good way to do that would be to teach him how to write his own mc mods. So I need to learn this quickly. I am only focussing on 1.12, not 1.13. Any good text tutorials would be great, as well as any 1.12 mods (github links) with good practices so I can review them.