I don't understand what to do.

Fellow admins, if such a topic already exists, please excuse me, but I couldn't find it. In short, I downloaded the "Legend of the Red Dragon" version of Heroes 3. It has missions, just like in all the other parts, but I don't understand how to complete it... They give you one peasant, and you wander around the map collecting everything that's lying around. But that's it; there are swordsmen standing in one place, and they won't let you go anywhere. They just threaten you with their iron stick, and if you don't manage to escape, they kill you. There's also a "secret passage" that, when you click on it, makes you lose your hero and fail the scenario. And there's also some random hero standing there, but he's not helpful at all. In general, please help me and tell me what to do next.