What if I create new istances? How do I make them in a container if they're two new istances?
This is done automatically; if you create any of the individual objects in a container, the whole container is created.
i.e. if you have SpriteA and SpriteB in a container, and an event creates SpriteA, a SpriteB is also created and is in SpriteA's container. This probably needs a wiki article <img src="{SMILIES_PATH}/icon_razz.gif" alt=":P" title="Razz" />