I would really recommend looking at the tutorials if you haven't. Stuff like the Ghost Shooter tutorial, or the Platformer school addresses a lot of the problems you seem to be having, and if you really go through them (and multiple times! like I did), you should begin to get a grasp of what you're trying to do. You can't really just run into things or else you'll hit infinite roadblocks.
The problem you have is this:
on the specific action "L key pressed" you have nothing happening.
What you need is something like this
-L key is pressed
-Sprite2 Opacity Equal to 100
Then: Set Sprite2 Opacity to 0
-L key is pressed
-Sprite2 Opacity Equal to 0
Then: Set Sprite2 Opacity to 100
For the lights (you should really get into the habit of naming your sprites), you do this:
Always (every tick):
Set Sprite2 to Sprite image point "lights" (I made an image point where the lights go).
Like I said, do them tutorials.