You can place your characters into the scene using spot direction:
Put your characters into the scene at random spots (ex. @JEMU776 stands screen center) and then use the spot helper to move them around and change their size. Copy the coordinates you get and input it into your script. (Just note for below, % stands for height, X stands for left, right and Y stands for up, down; more info in the spot direction article linked)
Ex.
&CHAR spot % X Y in zone # at layer # AND CHAR faces DIRECTION AND CHAR is animation
&CHAR2 spot…
(and so forth, there’s a pattern, replace the symbols with numerical values and you’d replace DIRECTION with either left or right, animation with one that exists-the zone, layer, direction and animation are optional to add, you can just write &CHAR spot % X Y but adding extra stuff helps more, if they’re in another zone, you must add the in zone # part for them to appear there)
Another resource which will help you:
There are cool script commands you can use like THEN/then which is so helpful in regards to background characters paired with &
You can also layer background characters: HOW TO: Move Characters / Overlays to the Layers
I hope all of this helps. I also have a tutorial on spot direction that you can check out, good day 
