Take a look at the below links for some good places to learn. I’ll be posting more as I go. Enjoy for now.
https://www.contractorsischool.com/contractors-license/earthwork-paving-contractors-license-c12.php
hthttps://study.com/articles/How_to_Become_a_Concrete_Paving_Contractor.html
http://www.cslb.ca.gov/About_Us/Library/Licensing_Classifications/C-12_-_Earthwork_And_Paving.aspx