What should the questioner do to return what he stole in his youth from a supermarket that no longer exists, and what is required of him to return what he stole from his mother when he does not know the amount and does not possess money, and how can he return what he stole from the bookstore owner who used to pay bribes, and is the bookstore owner's money considered illicit due to the bribes?

The financial rights you acquired before puberty do not cease to be your responsibility; you must return them to their owners. If you are unable to deliver the sweets to their owner, then give an equivalent amount or their value in charity to the poor. As for what you took from your mother or the bookstore owner, you must estimate its value and return it to them or seek their forgiveness. If you do not possess money, then you must repay it when you are able to do so. Paying bribes is forbidden, but it does not justify stealing money from the bookstore owner.