Bought a 96 Nissan Maxima amd when i locked the door the alarm went off nd doesnt go off unless i unplug the battery..I dont have the key for the door nd my car won't start how can I get car started

Alarm fuse maybe, you need to get a key. That's the best way for a vehicle to cooperate.

You need to get a driver passenger or trunk key to disarm the alarm... *With the door open, press the lock button.. *Then shut the door.. *then unlock it from outside the car, once you unlock the car the alarm should cut off and you should be able to start the car..