The "In search of hideout" quest is one that can safely be left until you have built up your town more and have done other quests. It continues the storyline of Gromus and the "Opposition". You should see the location, opposition hideout, on your world map when you look at it. But you might not be able to do much if you go there, other than explore it a little and discover that you can't get very far at the moment.
Far more important at an early stage is to work through the tasks that your two advisers give you for building up your home town and defences. These tasks act like a tutorial and are invaluable in developing your ability to play and progress... as well as giving you lots of very useful rewards as you work through them.
Once you have done quite a bit with these quests, then you might be ready to explore the Opposition Hide-out. You will need quite a lot of stone, and a bit of an army to complete everything in Opposition Hideout anyway, so again, it's worth focussing on tasks closer to home for a while.
