Bring up a timer clock on your phone. Put a timer on 1 second. Watch it go by. Now look at your Bitcoin and the transaction time. Watch a second go by again. Look at Bitcoin. Do you get, where I'm going with it ? 

I would be Etherium, I guess. I bet ETH will cost like 2k at the end of next year

I guess you could start off by getting urself a btc wallet and buying some bitcoin  Than choose an exchange, I suggest Bittrex or Poloneum

Removal of fiat is almost certain to happen sooner or later in majority of developed countries. I would be hesitant to estimate, whether it would be a good or bad sign, though. Cash has it's place and purpose. And it cannot be wired instantly from your pocket to some hacker lol 

I always test people by saying "cryptocurrency". Normally they just look really confused, and than I add "-well...bitcoin, you know?". And than I have to hold tight, meanwhile they are happily unloading on me what they know about bitcoin - normally it's something along the lines "unsupported, illegal, a lot of bitcoin used on blackmarket"