Hahahah this is pretty fucked up lol
I'm lucky that my parents don't know anything about btc or whatever...There wasn't a single news article about bitcoin in my country from the day it began.
If I was you,I would just show my dad some YT videos and see how that will go.
It won't help because his dad is a close minded person already because of a lot of illegal things that are coming out with the society on their place and the medium for those acts is with bitcoin. It's kinda hard to encourage and change the mind of his dad because his dad thinks that way by showing him on how you use bitcoin legally will simply make his mind change.
Most dads do really have close minds on which if they think its a bad thing they will stand on their decision until the end that's why we would really have a hard time on convincing them regarding to bitcoin.As in the OP mentioned his dad saw bitcoin is just an another scam that exist online.Therefore the best way to convince or change his view about bitcoin is showing him how to use it as a currency.