New Driver/ Dump Truck question

Hi all, i just have a few questions for drivers out there if they dont mind answering. I am 19 years old with my CDL A that i obtained as soon as i turned 18. For the past year ive been finding it difficult to find work due to my age, which is understandable. I currently work for a friend of my fathers who has me driving a 26' box truck. The job is starting to take a toll on me with its weird and low hours and low pay. I know this is probably the best i can get at this age but i am really interested in doing Dump Truck work. I currently reside in Bergen County, New Jersey and i always see on craigslist and local ads looking for Dump Truck drivers. I contacted some places and amazingly some places will accept me at my age, but the main problem is they want experienced drivers in the dump truck field. How can i get dump truck experience if every place wants you to have experience already? Even if i was over 21 companies still require 3+ years. To my current dump truckers, where did you learn?