To toggle between the difference types of world in Guild Wars 2. World vs World, PvP and PvE. There are two windows you should know. The Hero and World Vs World page.
In the hero page go to the pvp tab. It’s the last icon on the left side. Here you can “go to the Heart of Mists” and “Leave the Mists”. The shortcut key for the Hero page is (H).
In the World vs World, shortcut (B) press the “Go to World vs. World” and select the location you want to travel to. Notes that you can see what the scores are for the three worlds which is fighting each other without having to join it first. You can follow how well your home world is doing. If you are unsure which one is yours, hover between then until it says “This is your home world.”
Further read go to the Guild Wars 2 Wiki