Jan is a hunter in the bandit's camp. He was sent to the house outside the camp to be a lookout for the Order's movements. You will find him just after the tutorial part of the game inside the second house you find. He will threaten you with a weapon to find out who you are and what are you doing there. Talk to him and he will tell you that you need a decent weapon. Jan urges the you to head to the swamp and look for jobs there. He can show you the way to the Bandit's camp or the way to Harbour town.
He will not bear a grudge if attack and defeat him. He is worth 80 experience, small healing potion, lockpick and some gold.
Jan is in a house outside the swamp, on the road to the Harbor town.