Scratch

Um...

The background have this:

when gf clicked
forever
go to x: xscroll+480*0 Y: yscroll+360*0 

The player has

when gf clicked
forever if <key right pressed>
change scrollx by -5

key left change xscroll by 5

key up pressed change yscroll by -5
key down pressed chang yscroll by 5

so now i want enemys but i dont know how to make them stay in 1 place within the area

How big is "the area"?
The enemies would probably need this;

when gf clicked
forever
set x to ((scroll x) - (x)) //the "x" variable being a "for this sprite only" variable
set x to ((scroll y) - (y)) //and the "y" variable

The "x" and "y" variables would be the position of the enemies. You could make them move within a certain area by adding something like this;

if <(x) < [10]>
set [x v] to [10] //changing the 10 to the minimum x, if that makes sense...
set [x velocity v] to ([0] - (x velocity)) //So it turns around
end

if <(x) > [80]>
set [x v] to [80]
set [x velocity v] to ([0] - (x velocity))
end

Do the same for the y. Then it should work, I'm sure you can make them move...
Because it's velocity it would need for the enemy:

change [x v] by (x velocity)

So x velocity is just x speed. I would try to explain better but I've go to go somewhere...