I am a new truck school grad and have my CDL now. I have fond memories of our days out in yard playing with the school truck, and there's nothing like a day that has you 'shivering like a dog shittin' razorblades' to 'gettin' 'er dunn'. LOL.
If you do your pretrip like learning the lines to a play, you'll have it made: just remember, the examiner at the DOT, (or in Canada, the MTO), is human too, and they aren't there to fail you, but only to help you. So what, you forget to mention some aspect on one side of you tractor/trailer, as soon as you remember it on the other side, bring it up to the examiner, and carry on.
We only had 8 minutes to Pre-trip on our examination before doing the air brake and road test. Try pre-tripping your own personal vehicle for practice, and make sure to drink loads of beer - it becomes a lotta fun! LOL.