Welcome Elisha to steemit! Here are a few posts that may help your dad better understand how it all works:

https://steemit.com/steem/@teamsteem/the-ultimate-steem-guide
https://steemit.com/steem/@teamsteem/steem-an-in-depth-overview

And as for "central banking", perhaps this video by @dollarvigilante (currently one of steemit's most followed users) will help set your dad straight:

Throughout history there have been alternative currencies. As long as people accept them, they have even become the major currency when governments inevitably crash and burn. Now, this is not to suggest any crypto currency as an "investment" (certainly not at these levels), but the only real qualifier for "money" is the confidence people have in accepting it as a "means of exchange".

Finally, as your dad is a school principal, I feel compelled to share this with you and your dad as well...

https://steemit.com/creativity/@alexpmorris/do-schools-kill-creativity