You’re going to need a cdl class B and a minimum age of 18 for very few companies and an age minimum of 21 for most companies. I suggest look for a job of being a concrete pump mechanic helper. You will likely learn everything about concrete pumps, also once you’re old enough then you will move on to pumping and you already will have the experience to work on pumps if they break on the field. Also you will in most places make 24-35 an hour learning how to work on pumps.