Well I often hire drivers for seasonal work from around june until late october as concrete mixer operators.
I usually get fresh out of the school guys or school bus drivers looking to drive for the summer. Since my outfit is small and family owned we often hire green drivers and teach them all about being a mixer driver, but getting the CDL does require a truck for the driving test, and you need a medical card.
My son will be 19 next february and I am already teaching him all about air brakes, range selectors, shifting without the clutch and most importantly inspecting your truck for safety defects. and he will hopefully go straight for a CDL here in Alaska. We can never get enough mixer drivers, I can get truckers but they often fall short when it comes to the actual process of delivering concrete, its local but for here in rural Alaska we often have deliveries an hour or more away.
Maybe a small company with delivery trucks like fast freight, bread delivery or even local produce will train a person and supply the vehicle for the road test, I started as a mechanic for school busses and they supplied the bus for my road test and eventual CDL.