Car won't start

1998 mercury tracer-

Car doesn’t start, makes no sound at all when key is turned. After removing the key, engine light and shift light stay illuminated and the gps plugged into lighter stayed on. Normally there is no power to lighter with ignition off and key out. Headlights don’t come on and remote entry doesn’t work.

We tried to jumpstart-still doesn’t start or make any sound at all. But the two dash lights went out once the cables were hooked to other battery. After disconnecting, dash lights remained off as well as power at lighter.

Battery voltage is 12.16v and it’s only 2.5 years old.

Could it just be a bad battery?
Does the fact we couldn’t jumpstart it indicate a problem other then the battery?

Have that battery tested. Some batteries quit early

If the battery was bad and we tried to jumpstart the car, would it still not start or make any sound at all? Or would this indicate another problem?

Thx