I need some tips and help

Attach is the whole stage. What do you think is the parameters?

onClipEvent(load) {
_x=Math.floor(Math.random()*width) //where width is the width of your stage
_y=Math.floor(Math.random()*height) //where height is the height of your stage
}

Size of stage: 800px by 540px

If you only want the sheep to appear in the green area then you need to find out what the height and width dimensions of that area are.

Simply clicking on it and looking in the properties panel should tell you this [ thats assuming that the geen area is a seperate object ].