If I understand correctly you want the ball to move to a random position in the Grey.
Your call sets the position of Normie somewhere between 0 and 1376 for the X and between 0 and 871.5 for the Y.
I'm not positive but it looks like that your Grey area does not start in the top left (first pixel) of your game. What you need to do if find the top left pixels location of where you want them to spawn, lets say its (200,50). Then you find the size of your Grey area lets say (800,100). Then you start the range at the top left spot and add a random(width) to the X and a random(height) to the Y.
Start of Layout || Normie set position to (200+random(800),50+random(100))
TYSM!!!!!!!!!!!