Guildleves are the means by which the Adventurers' Guild organizes and assigns the various requests made by the citizenry. To accept your first such task, make your way to Horizon and speak with Totonowa.
In order to gauge your ability to handle the various guildleves he has to offer, Totonowa requires that you carry out a preliminary task.
You have successfully completed the trial guildleve. Report to Totonowa at Horizon.
Totonowa is now confident that you are capable of handling any of the trials and tribulations you might encounter at Horizon. Prove your worth as an adventurer, and continue to undertake the guildleves he has to offer.