Bad starter relay?
 

My battery just died so put in a new one. 2 days later I turn on the key and nothing, no click from the starter, all power, interior lighting, gauges all went dead. We jump started it, started right up, then drove it home. Got home, turned it off, tried to start it and the same thing. Thanks in advance, I can't stand electronics.

Year of car? Any aftermarket stereo system, car alarm or remote locks?

Try to determine if the battery was really dead or a problem with the battery cables that made it seem it was dead.

If dead and the new battery now dead, determine if there is a too large of train drain on the battery when ign key is off.