I bought a 1996 Honda Logo about a month ago not knowing it had an alarm till today!! It just started going off :/ every time I open the the door the alarm goes off!! How can disconnect the alarm?

 

look for an alarm brain underneath your driver dash.

though i'm not familiar with your model honda, it's most likely an aftermarket alarm.

 

Do this when you're at home and no where else as this will cause people to look at you:

Let the alarm go off when you open the door, now listen for any clicking noises in your dash, specifically near the fusebox