If you never played WoW before, I suggest you play the official one before dabbling with emulators/private servers, it's a much better experience if you know nothing about the game.

WoW client is not native on Linux but it runs flawlessly regardless, always have, it's also very easy to install with Lutris: https://lutris.net/games/world-of-warcraft/, use the battle.net script and follow instructions to install dependencies first.