There isn't much to making a single player map.

• You need to set up two players: the enemy and the person who will play your mission.
• You should set a waypoint "initialcameraposition"
• The firepower that the player has should be enough to win, but should demand some tactical ability from the player

This is a video that will show you how to set up a simple singleplayer map.

Get map, zipped

Show video