well it helps to know what class/profession you want to be, and how you want to start, do you want to mostly do bgs for fun? rated bgs for seriousness, arenas? 2v2s, 3v3s? 5v5s? They make a difference. Mostly learn to keybind everything important because in a pvp scenario you cannot and will not have the time to click things. Also, don't get too frustrated, the game isn't balanced per say, so you will encounter dumb matchups that will frustrate you but nothing is unbeatable.