If you want open world PvP, the closest you'll get to that is the duelling circle at the Wolves' Den - Yoshi does not support fully open world PvP because he does not want new players or casual players to be harassed by high level players just wanting to gank them for no reason. Besides, PvP period is not FFXIV's primary focus, it's side content rather than the game's whole point. FFXIV is primarily PvE focused, and always will be - open world PvP does not work with that.