I Have a World-Famous Copper Coin

Lin Lang, a pariah in the city, sneaked into the ranks of the city guards in order to have enough food, but he almost died several times. There are monsters outside who are watching covetously, and there are children of the Immortal family inside who regard human life as nothing. Lin Lang can only survive by relying on an ancient coin passed down from his family. I don't want to practice, I just want to survive...