I set my burglar alarm last night but this morning none of the lights are lit, including the red active light. I put in my code, but am afraid to open the door because I might set off the alarm all day. (my instruction manual is in the garage, which is activated) Help!:)

Wonder if you lost AC to power transformer or transformer? Battery would have taken over and may went dead as well.
If power is all the way down, it shouldn't trigger the alarm.
Any way to test any voltages?
Manufacturer/Model of Panel?

Thank you for your input. I finally got the nerve to open the door and no bell, so I guess the battery is very dead. Don't know if the battery is the only power or not. Have an alarm company coming to check. It is a Napco system

I would check all circuit breakers, You may find a White or tan transformer plugged into receptacle, receptacle must have power,
AC power keeps the battery charged, The battery takes over during short power outages.