TheHunter/Missions

On your My Page dropdown you will have a tab for Messages. Open this and you will see some default messages from the games NPC's. You can click the message, then click the text next to your avatar to reply to the NPC. The NPC's will give you a variety of missions.

Once you've accepted some missions, you will get a window on your main page that shows your current active missions as well as the ones you've already completed.