you could always get the books :3 to my knowledge WoW was built up from the 3 original games (the 3rd one having two different versions-- reign of chaos + the frozen throne), and books. There is so much lore you can read on for a good few days on the website if you want to know every little bit of everything (im like that

), the books put down very key events but there is lore that is lost and the authors dont neccesarilly follow the games real lore so theres some conflicts
Edit: the original games and the books are the only non-online things i know of to find out lore (im pretty sure the old games dont need internet)