IIRC, the three age choices at character creation correspond to 5%, 10%, and 15% in the basic skills of a nobleman (which include, but are not limited, to, swordfighting, jousting, and leadership).
In general, getting older is not of any benefit. Eventually, you will no longer gain as many hours per day, your skills will degrade faster, and you will not heal from wounds as quickly.
But all of that is a ways down the road for you.