ecu box problem

You cannot tell a 5 pin box from a 4 pin by looking. Many of the aftermarket replacement boxes are "4 pin" but actually have 5 physical pins. Only way on unknown box is to check resistance off the 5th pin to the others

Most/ all NEW replacement boxes will be 4 pin

And "no" you cannot hurt anything with this box

I would run the car and wiggle the connector. Hold the connector in and gently tug on the wires which come out of the ECU connector one at a time