Yes you need to run the trainer first, but no, you run only the trainer as administrator, not the game.
Having the same issue but the trainer icon does show in my task bar and task manager. I am getting no GUI though. Clicking the icon for the trainer does not bring up anything. It works in the background though so I can still get the cheats to activate but this means I can't use the editor as there is no GUI.
Lower your resolution to 640 x 480 and recenter the trainer's GUI.