Kaldheim is a realm of, gods, monsters, and Norse-inspired elements. There is adventure, but It's not an adventure set in the same way that Zendikar is. Here, people want to do epic feats in battle so they can be remembered in sagas told by their clans. While there are gods and heroes, as in Theros, it's a very different tone here. You're more likely to have a beer with a god on Kaldheim than worship them. Gods are more powerful than humans, but they are mortal here.
Commander is a fun one-on-one or multiplayer format with slightly different rules compared to a standard game of Magic. You can join in the action with one of two pre-constructed decks hat are ready-to-play straight out of the box.