Custom Enormous village

Hello, im new to minecraft coding, modding and datapacks in general, but as im making an RPG modpack, with some custom stuff, i needed to learn how to make custom structures, that includes some boss arenas, randomly but calculatedly spreaded around the world and of course, a very huge start village, that would have big walls, a lot of different houses and stores, markets, a big castle. But i dont quite understand certain parameters used in datapacks, like size, weight, and i can't even spawn entities like iron golems using jigsaw blocks, what should be easy to do. Anyways, im focusing on villages right now and i found out that i can put up the size of them to 20 (instead of 1-7) on the worldgen/structure/json, and of course, turn on the expansion hack, but it simply doesn't seem to work, im trying everything for like 4 days, they're simply small, and kinda nonsense, if someone could help me, i would be really glad I'll be leaving the datapack link here if anyone's interested to see if there's any mistakes with paths or code