You are far from a Stone Age kid but we could have had fun back then. I always wanted to BBQ a Mastodon.
FO = First Officer, now commonly called SIC or Second in Command, previously known as co-pilot.
Years ago, it was, "don't touch anything unless I tell you to" which slowly became CRM or Cockpit Resource Management, which is usually defined as using all the resources available and don't leave anyone out.
Best regards,
RA1