After Aang’s era has ended, Korra’s began.
She’s sort of a prodigy.
Very eager to be the avatar, to help people, to learn more styles of bending all four elements… But she’s been sheltered her whole life. For safety reasons.
At the age of four she displayed waterbending, firebending and earthbending.
Though born in the southern water tribe, she prefers firebending. that’s her whole presonality.
So she goes away to learn about airbending from Aang and Katara’s youngest child and she gets first glimpse of the outside world.