I think you mean the bar's basement.
you can craft torches at home or after you complete the bandit camp questline you can unlock an amulet that glows permanently when equipped, for that you need to go to new forest you just unlocked after the bandit questline is done and explore it until you unlock the troll bridge which then you need to look for another way around the bridge and find a cave with glowshrooms/worms, I don't remember exactly which. last step is to choose between the witch or Othra for the amulet.