How can stolen money be returned to the father if the thief does not possess the means to return it, and are the calamities and tribulations that befell the thief due to his sins?

The money you stole from your father is a debt that must be repaid as soon as you are able. The fact that your father gifted you your belongings does not prevent you from selling them to repay his debt, as they have become your property to dispose of as you wish. Sell from them what exceeds your needs and use the proceeds to repay your debt. What remains is your responsibility until circumstances ease for you. As for calamities and tribulations, their cause cannot be definitively determined, but hastening punishment in this world is a possibility, and sin has a detrimental and inauspicious effect that impacts a person in all their affairs.