Save, using File > Save As so as not to overwrite the original. Then go to Play > Quicklaunch Map to have your creation loaded into a default Sup Com skirmish match. Before you get bogged down in robot building, have a thorough check around to make sure everything works. Can units access the island OK? Are there too many props? Are there enough resources? You’ll have to do a wee bit of testing before the map’s ready for public consumption.