The reversed Ace of Pentacles indicates that your son Damiano has a negative approach to finance and money. He is not sure how to handle his money and therefore may have a lot of trouble saving money.
The reversed Nine of Wands indicates that, despite being aware of the situation, your son Damiano is unable to overcome his fears or resistances regarding finances. He may be bogged down by worries or doubts about the future, fearing that he won't be able to put away enough money to meet future expenses.
Finally, the reversed King of Cups indicates that your son Damiano needs more awareness of his current financial situation and the need to act with caution. He might be tempted to spend all of his money without thinking too much about it, but that's not the best way to save money.
In conclusion, the most appropriate advice we can give your son Damiano is to be aware of his finances and try to make reasonable decisions about saving money. They will also need to learn to address their fears and worries about finances so they can make more informed and effective decisions.