Something that tends to get people is the fact that each state has the right to set up their own CDL test and approval how they want. Of course at a minimum they must observe the federal level requirements but they can add to them (just not take away).
So you must check with your state to see what additional, if any, requirements they have.
One of the more common requirements is the completion of an approved driving school. These can range in length and cost.
If you are prior service military with, commercial level driving experience, most states will waive the school requirements. Check with your local VA rep for more information regarding this.
I did say life as a truck driver can be challenging. But it is well worth it as well. As there are many good things that come from it. One of the best benefits is being your own boss. Oh sure you have schedules to keep and such, but your truck and the open road is your office.