You can create an at begin of scene action
inside of the scenes action tab for automatically triggering actions at the beginning of the scene. You can also create called by other actions
& call them inside of an at begin of scene action
As for the doorways/entrances/exits, you need to...
a. create a foreground version of the wall or part of the scene/doorway that the character should walk behind & add it to the scene as an object. Don't forget to set the correct object center for it.
b. you should draw your way-border for the scene so that it extends behind the doorway or even outside of the scene background itself. You can move the scene viewport around by moving mouse cursor over the top of the scene viewport & then middle click, hold & dragging.
You set the character position for the exit/entrance object so that the character is positioned behind the foreground of the doorway.
Hope this helps, clear some things up.