Where can you find a private truck owner to rent for a cdl licensee?

Unless you already have connections, good luck. Do you really think an O/O or small fleet owner - who has the ever increasingly difficult task of paying for the trucks, maintaining them, and paying the insurance - is going to simply rent one out for a brand new driver who they don't know from some random person off the street? You'll probably have to have your road test administered through a truck driving school.