I'm new to this, but I think everything imported into Character Animator is a "puppet." At the bottom of the project panel, there are two buttons. One has a puppet icon, the other a scene icon.
In terms of changing scenes, drag it onto the screen and then it will appear in your timeline. From there, you can change it's length. So in order to get different scenes, just import them and then put them into the scene and change the length. It's irritating but everything imported into a scene starts from the beginning and goes for a long time. You have to grab the handles to make it longer or shorter.