Thorin’s story basically explains how his family's wealth was taken from them bye smaug. It also tells of their town, dale and what would go on there, like for an example they would never grow their own crops, they would trade for food and supplies. Also about how everybody loved them, they would send their sons to become apprentices. I don’t blame them, it says that they would richly reward the blacksmiths that had the least skill. This town of there's was also magical, as it says that they would craft magical toys. After this it explains why smaug attacked them, as dragons are attracted to steal other peoples gold and jewels, after the attack no one ever came back in fear that smaug would get them.
This is where the story begins, in Bilbo's hobit hole.
RAWR, Gimme your gold
Thorin explains how his family had build this wondorus city Dale.
WOW, A giant cave
He also explains how they were super rich and would pa for everything, even food.
But, Dragons are attracted to wealth, so the dragon, SMAUG attacked
Luckly Thorin was outside wandering, so he was ok.
Though, while he was out the city of Dale was destroyed and only a few survived