First things first, you need to find all th books in order to learn goblin language: one from Herta, one from the goblin slayer, one from the scholar in the first village(the one that gives you the misterious book quest), and the last one from the militia girl in the vllage where you get the slave girls quest. Total of 4 books. Once you've learned, you need to have almost 30-40 red crystals(you can get them from the goblin slayer 3 at day) for purchase the permanent map once you get into the village. if i forgot something, please all, correct me.