I couldn't have said that better myself.
I'd like to add that in Showmanship, (in MY fairs, it may differ for yours), 95 of the 100 points is all based on the answers YOU give. (There's a grading sheet with different topics all about the things mentioned above. The points for each topic are usually out of 5 and 10, the more important questions are out of 15 or 20. Added up, the total is usually 100.). So that means, at least in my competitions, 95% is primarily stationed around the exhibitor. That leaves 5% left for the bird. It's alot like reversed regular-showing. Showmanship is for the person, showing is for the chicken. Of that 5%, it's a pretty simple 'you have it or you don't'. If the bird is lice and mite free, looks clean and doesn't have any obvious DQs (even then, some judges won't care!), it will usually get the full 5 points. Great quality usually helps, but the bird does not necessarily have to be really special. At least that's how it works for me.
I forget, however, that this year our fair was out of 110 points. Point being, they can add questions/topics or remove them from the grading sheet every year if the judge feels it needs to be done.
Gather as much info on your breed and general chicken-stuff as you can. Go through how you take care of them, how to maintain healthy birds, etc. Practice alone or recite answers to a friend or family member. That way, when you're standing in front of a judge, you don't get nervous.
Showmanship has a dress-code. I wear a white lab coat. You're supposed to dress 'nice' in a nice pair of black pants and a nice white shirt, or a lab coat. Lab coat works better for me. Another important thing is to smile, really listen to the judge if he/she is responding to something you said or if he's/she's asking you a question. Be respectful and polite of course. In my fair, all of that together is a good 30 or so points.
As far as the parts of the chicken body, you can probably find a few good diagrams labeling the general stuff. I suggest, though, that you take a look at this page. It's also in my favorites.
https://www.backyardchickens.com/forum/viewtopic.php?id=343605&p=1
I memorized the first wing diagram and well as the one of the feet, and drew my own silkie and labeled the parts of the body on the paper. VERY useful. Read up alot on here. I wouldn't have gotten anywhere if not for BYC. It's my deadly weapon against my fellow 4Hers.