Opening
You start off in Banjo's house during a stormy night with everyone (Mumbo, Bottles, Banjo, and Kazooie) playing a game of cards. To sum things up, considering this scene takes a while, (Spoiler Alert!!!) the witches sisters come back to save her, which comes up nothing but bones, and eventually ends up killing Bottles. If you've never played any Banjo games then it's recommended that you go to each of the molehills to learn how to do each move that Bottles teaches you in the last game. If you already know all the moves then you don't need to check the mole hills.
Spiral Mountain Stuff
You are probably going to have to come through this area a few times during your game.
Boss: Klungo-Minion With a Mission
Almost immediately after you start playing, Grunty's assistant will run into a cave and you must follow him.