Why approach it from this angle? If you already know how to drive you can rent a truck for the test. If you need minimal training and can afford it try a local tech school. They often don't charge much if you just need a refresher course. If you need to be throughly trained why not go thru a company program? Some of the small companies where I live were able to steer me in the right direction without a lot of strings attached.
You can rent big trucks just like you rent a car. Ryder, Ideal lease are two that come to mind. The local trucking school will also test you on their truck for a low price. To rent a truck you need someone with a cdl to take you. Good luck