Open both doors to main control panel, you will see were the dvd-blue ray is plugged in, off to the side (around the corner from main controls) you should find the switch you are looking for with many others.
If it is the awning lights you are looking for that switch is in the garage, if it is the other lights, those switches are hidden around the corner in main cabinet. Good luck and enjoy the new rig, we love ours so far.