How To Make a REAL Guns in MCreator

Hi everyone! I am going at modding again and really want to make guns a feature within it. I was wondering if anyone knew how to create a 3D gun in MCreator, with a reload animation and everything? I absolutely love Flans mod and Techguns, and I really like MrCrayfish's Gun Mod as well. So, what software/programs should I get? What websites could help me? What kind of code do I need to actually build the weapons I have in mind beyond the skins I make them? If anyone can help me, I would be deeply appreciative ^_^

Thank you all =D