you're working and earning something, that shows you can give them a reason to believe what you told them about Crypto,
I'm sure he needs more time to do that. It wouldn't make sense to say anything if he just started his journey, he can only prove a point in front of his parents if his investments start to earn him money because only that will make them believe Bitcoin and cryptocurrencies aren't scams but they are an industry where one can invest and earn money if they know what they are doing.
and they won't understand what will come out of investing in Bitcoin and I'll say since you know they have no knowledge about Bitcoin you should continue to live up your dream to be a better investor and don't let their words to discourage you in any way.
Parents will never discourage their children, so they were probably not trying to do that but they tend to get concerned and if they have traditional beliefs, it will take time for them to understand what these new things mean and how they work because they have never heard or seen of anything such as Bitcoin in their entire lives before.