Heya! All you need to do is set the Bounds for the room (so the camera knows where the edges are and doesn't go outside them). You can do that either by dragging the yellow box in the scene, or settings the width/height, etc in the Room's Data.
Some extra info about scrolling cameras:
- You can leave the Y, and Height at zero if you only want to scroll horizontally
- You can set the scroll bounds the same way. These control how far the character has to be from the edge of the screen before the camera starts scrolling. By default it'll try and stick to the center of the character.
- There are some more setting that control how the camera moves/scrolls in PowerQuest -> Tools -> Game Camera.