If you are unsure enough to ask then I would suggest a school or experienced tutor before getting behind the wheel.
It's not like driving a car...you will need to pay far more attention to details since the rig takes up a lot more of the road so there is less room for error. Don't let that statement scare you too much. It most certainly is doable for almost everyone! But that means you also need to be concerned enough to learn and you already seem to realize that.
One other important note...if you are 1/2 of a couple who will be traveling together, I believe both of you should attend the school and drive.
Relax, take your time and have fun!