[Jackel9]

Ok first of all if you want to make a gmap with a terrain like trees and so forth yo will have to do it in paint(ask for colors later on)
Then you would have to the level generator and load the specific gmap image (png is best). Make sure you make a specific folder for the gmap and rename the gmap levels where it says myworld_ to newname_

Then when you arei n editor mode go make a script saying

if (created){loadmap newmap;}

Then an arrow would appear for you to look around the gmap in editor (non playing ) mode.

hmm i think you can do

function onCreated(){
loadmap;}