Titles don't really affect gameplay, but just fun little things you can use to "personalize" your profile, etc. :) Most titles are gained via forum games when Fai or Krin host them during events.

https://www.sylestia.com/forums/?thread=60339&page=1#1 An example of a game that had a title for a prize.

However, you can obtain a couple outside of these forum games and events.

For example, "Warden of Umbra" if I am remembering right is gotten when you first get through the Dungeon of the Forsaken in Umbra Forest.