Get all the endorsements, even if you think you won't need them. Endorsements are money in the bank. A new cdl grad with tanker/hazmat endorsement can make $65K.
Even reefer drivers need hazmat endorsement because sometimes there may not be a refrigeratedu load available, but there is a load of paint. Because you have the hazmat endorsement you can roll down the highway instead of sitting in a truckstop waiting for a refrigerated load.