Pull Sims out and clean them off with a Qtip Then blow any dust out of where the sims go Try that first I once had the same problem turned out to be lint in the Sim Card Tray
Sounds like your Battery has died. easy and cheap to replace. Buy new battery from Amazon Take back off back of phone, pull out the battery Put new Battery in Charge Phone Start up phone
That's trouble right there. It looks like a Nonelectrical connector that holds something at a 90 Deg angle. I thinking a holding the charging port in place ?
buy a can of compressed air and clean the fans air ducts. Be sure NOT to make the fan spin as you can damage the motor. have a vacuum nearby to clean up the dust.