We have always just got the hand book and studied it.   Take the written test and get a learners permit good for 60 days. Only problem is now you have to have a CDL driver with you when you practice drive a cdl vehicle.  22 years ago you did not have to have one with you when  my wife and I got our CDLs.  We had toride with my SIL   8 years ago when he bot his license. The pretrip inspection is what  most people  foul up on.