Let him learn for a few years. The only mistake would be getting married and being financially incompetent at that time. If he can afford to learn for a few years, let him learn. When he’s ready to get married, he has to do what is necessary to earn a living (whether that be college, have a job lined up through connections, etc.). The important thing is being able to make ends meet. Once that is met (and it’s very easy for most 18-year-olds) he should learn as long as he can afford it.
