Actually you get it by advancing the storyline quest. The first part of the quest has you go to the first camp, after doing that, go back and talk to the head of the adventurer's guild, and you will learn the ability.
Yes, all you need to do is continue with the main storyline started once you arrive on the mainland. Nothing fancy will happen, but you will see that the ability is added to your list. This is completed once you visit your first starting area and return to the guy who gives you the personal linkpearl for communication.