Map editor works, now what?

[hammer62]

OK Everyone, I can see how to start the editor and it seems like a very long process to creat a map. I tried to load up a map already created that I downloaded called Winter Map, but can not seem to be able to open it up and play it. I try and find the map in the editor but with no luck. What am I doing wrong? Is there a random map creator for this game? I want to play a large map and just take my time and roam around and fight, level up and find cool things. Any suggestions?