How can I open my hood, if my battery dead and I only have a automatic key

Assuming that the car is locked and that you don't have the key "blade" itself to manually unlock & open the door? If you have Roadside Assistance (thru Honda or AAA, for example)..or if someone in your household does....they can unlock the door with a "slim jim" (Cops used to be able to do this...I've heard that some cannot do this now).

Opening your hood has nothing to do with the electrical system, unless you mean the trunk not the hood. Either way, if you are or can get into the vehicle, just pull the Hood Release leaver under the dash board or the trunk release lever on the floor.

I understand the hood release is under the dash, but how do you get to the hood release if doors are locked and the battery is discharged

My car alam open but I using key open than my car alam on but I can't open my bonnet