KonkorFour - If you do want to treat layouts as levels, switching between them is pretty simple. Look at the System action "Go to Layout" (you can read about in the manual here). I recommend reading through the whole manual when you can - it really does help.
Basically what you want is to detect a collision between the player and the green square and call "Go to layout - Level 2" (or something along those lines).
For your second question, you can right click an object and move it to another layer that way, although I'm assuming that both are actually on the same layer and that what you really want to do is change the z-order - check out the manual entry on the z-order bar here.
Can't stress enough how helpful the manual is - it's rare to have one so well organized these days, so it'd be a shame to not use it ;) Going through a few tutorials and the example files is big help too.