Is 18 too young to start a saving/investing money?

I am leaving for bootcamp in a few weeks. I am starting at E1 pay grade(so roughly 1k base pay a month after taxes).

My parents are saying I can’t spend my money on anything. They’re saying I can only spend $200 a month maximum on food, clothing, necessities. My dad wants my pay check to go into a joint account so he can save my $800 a month. Now whether or not he saves or invests it is a different story.

Now do my parents have any sense into what they’re trying to make me do? Is 18 a good age to dump all of your money into savings/investments?

What I had in mind is putting 500 into savings and 500 spending a month, since the military life is pretty dull on your off time. I’m into cars so I was thinking about putting alittle aside every month to modify my car(since I’m into these things). But my dad has other plans.
Update: I was taught growing up that if I wanted to spend money on something I wanted, I’d have to work for it myself. Which is one of the reasons I wanted to go into the military in the first place. Quicker way to get $ instead of sitting through 4 years of a costly college.

But now my parents are saying I can’t do what I want with my own money, which kind of means they fed me bs all my life. If that was the case then I would become a nobody and stay at home all day off of their food/housing.