Looking for my first scenery add on

Out of range just means you can't see it.  In FSX, if you can't see it, it doesn't exist.  FSX generates your scenery as you fly closer and closer to it, or further and further away from it.  It's level of detail (LOD) is constantly changing.  As you fly further away, the LOD becomes less, and vise versa.  LOD is an adjustment that can be changed in the FSX.cfg file, as well as other places.  Hope this helps.

Keep in mind, I may have no idea what I'm talking about.