The structure of the Kalevala as composed by Elias Lonnrot is a topic in and of itself. The following selections emphasize essential themes of creation and art, which I recommend as central to our discussion. The Kalevala is also rich in epic themes of vengeance, rivalry, courtship (Cantos 18 - 19), contests and adventures (Cantos 26 - 27), and the supernatural, including an apocalyptic war and restoration of the world (Cantos 43 - 49), and bear fights! So, I suggest you sample additional Cantos as your reading time permits.
Cantos 1 & 2: creation
Cantos 6 - 10: forging the Sampo
Cantos 16 - 17: the journey to the underworld
Cantos 37 - 38: forging a wife
Cantos 39 - 42: theft and music
Canto 50: the birth