If you're the one fixing all computers in your family, you also know how a system administrator feels and what he/her dreams of: automation, removing user privileges as much as possible, tools for automation, tools to reproduce an issue without access to the computer and its user, etc.
For each major language, Google for "why use X".
Ask your developer collegues what's their favorite language and the one they hate the most, nobody will tell you the same reasons. Ask about language choice according to the context/task at hand. You'll have most fun if you can ask this when you have multiple developers around, you're in for a nice informative flamewar.
I recommend skimming a book like "Computer Science An Overview" to get a handle on some key ideas an terms. Then you can look at some case studies from from industry to find out about specific technologies. New technologies and buzzwords come all the time, so try not to get too hung up on specifics. Good luck!
My condolences on the sudden job transfer. I work in Japan too and the practice of moving employees to completely different areas of the company every 3 years is one that needs to die quickly.
Example (not super accurate but can give you general ideas): http://carlcheo.com/wp-content/uploads/2014/12/which-program...
Plus, I'll be moving from recruiting to sales, so I'm expected to know a bit more.
I imagine the same thing goes for salespeople