From Aeria Browser Wiki
Side Tasks are missions that you will basically do anyways playing the game, unless you are only a diehard PvPer and only do sport fights (but then you will miss so much of the game). The most stable Side Task you will have is leveling. Every time you level you will get a quest to get to the next level. The other predominant tasks that will show is to do a boatyard scene at a certain difficulty. If done it should unlock doing that particular boatyard scene at that difficulty level as a daily task, but more on daily tasks in the next section.