Fantasy book: blacksmith/mage boy, a giant troll and a boulder rolling into the village

Question

I remember there being children who come of age to be apprentices. There is a whole ta do about being chosen. There are a boy and girl character that I remember. The girl is chosen to be a muse or seductress type? Boy was a blacksmith or mage type of person. If not a blacksmith he visited the blacksmith a lot.

At one point there is a run in with a giant troll and a boulder that rolls into the village and destroys some things. Also the boy sneaks out and from his room hears something and climbs down to and takes food to something. Also sneaks through tunnels. He ends up leaving town after troll and boulder incident and buys a horse.

Answer 1

I am not certain, and it is a long shot but it sounds a bit like A Companion to Wolves:

A Companion to Wolves is the story of a young nobleman, Isolfr, who is chosen to become a wolfcarl -- a warrior who is bonded to a fighting wolf. Isolfr is deeply drawn to the wolves, and though as his father's heir he can refuse the call, he chooses to go.

The people of this wintry land depend on the wolfcarls to protect them from the threat of trolls and wyverns, though the supernatural creatures have not come in force for many years. Men are growing too confident. The wolfhalls are small, and the lords give them less respect than in former years. But the winter of Isolfr's bonding, the trolls come down from the north in far greater numbers than before, and the holding's complaisance gives way to terror in the dark.

Isolfr, now bonded to a queen wolf, Viradechtis, must learn where his honor lies, and discover the lengths to which he will to go when it, and love for his wolf, drive him.

Source: Amazon description of A Companion to Wolves

It could also be The Elfstones of Shannara:

Allanon returns, having spent the intervening years in magical sleep, and conscripts Shea's grandson Wil and elven princess Amberle to save the world. It seems that long before human history, the elves (revealed to be the real thing, not mutant humans) and other good faeries locked all the evil faeries, known as Demons, inside the Forbidding, using a magic tree called the Ellcrys. Now the Ellcrys is dying, and the Demons are beginning to escape. Amberle, as the last of the Ellcrys Chosen, must make the journey to the Bloodfire, to fertilise one of the tree's seeds. Since Allanon will be busy helping the Elves defend their homes from the Demons, he convinces Wil, who has inherited the anti-dark magic Elfstones that the Druid gave to Shea, that he must protect Amberle on her dangerous trek.

Source: TV Tropes page on the Shannara series