Tip#1 - If you enter (your entry) just near closing (a day or two before closing dates) you will most likely be placed at the end of the lineup, which will allow you to watch the others ahead of you go first. It may relax some of the worries for you.
Tip #2 - Let the stewart (judge's helper) know it is your first time and most of them will help you out - when to go into the ring - things like that.You will get your number - arm band for the stewart.
Tip #3 - buy a catalog when you get there at the show and look at the pages for the yorkies - it will give you the numbers and order of the lineup. You just follow suit. If you win your class - hang around since you will have to go back in for winners.
I use to do so much better showing when I was younger - I didn't know what to worry about.
Good luck and let us know how it goes.
T.