You don't need any sort of special license for driving a commercial vehicle if that commercial vehicle is a car or a pick-up or anything like that. CDL is short for Commercial Driver's License, but not all commercial vehicles fit the bill. 
Just about any car you'd consider driving as a personal vehicle can be driven with a standard driver's license. CDL's start to come into play once you pass a certain weight limit.
CDL Class-A
Class-A vehicles cover tractor-trailers, livestock carriers, flatbeds and truck and trailer combinations. You will need a Class-A license if you're driving a vehicle (or combination of vehicles) with a combined GVWR (gross combination weight rating) of 26,001 pounds or more, if the towed vehicle is heavier than 10,000 pounds.
CDL Class-B
Class-B refers to passenger buses, box trucks, dump trucks and tractor-trailers. This covers up to 26,001 pounds, with towed vehicles under 10,000 pounds.
CDL Class-C
Most business owners are probably going to be looking at a Class-C license. Class-C will cover 16-occupant vehicles, HazMat trucks, passenger vans, and smaller combination vehicles that are not covered by Class-A or Class-B.
Driving a Class-A, B or C vehicle without a license is illegal. So, buying a commercial auto insurance policy on such a vehicle is sort of a waste of money if you're not going to actually be able to use the vehicle.
Before investing the time into attaining a CDL license — and the money into buying such a vehicle — it's worth considering whether you really need to. There are far fewer regulations affecting trailers, so investing in something you can pull with your Ford pick-up may save you thousands of dollars and countless hours of training and paperwork.
Of course, it feels good to look in your wallet and see a Class-A CDL license. But, if you're running a business, you need to put some thought into the bottom line. Most small businesses really don't need much more than a pick-up, a van or a medium-sized trailer to run their deliveries and pickups. Not to mention, these CDL vehicles cost considerably more when it comes to commercial auto insurance.
If you need a bigger truck, you need a bigger truck. But it's a good idea to stick with smaller vehicles while you can.