Are her parents champions? Grandparents? Just a scattering of champions in her pedigree isn't enough in today's competitive show world. She should at LEAST, at the very minimum, be champion sired. And hopefully both parents and grandparents have finished as well.
Yes, as Chloe said, get her used to being stacked. Both free stacked on the floor and also on the table. Get her VERY used to having her teeth examined. And every part of her touched when she's on the table. A puppy may move a bit, but she should be standing quite still by the time you are ready to show.
Do you have a grooming table? I'd get one if you don't so you can practice, or you can use the top of a washer or similar if it has a non slip surface. Many, Many people who show Chi's use a stacking set which has four pads for feet and nothing else, so it can't move around. If it does, it will be very off balance. They quickly learn to stay still.
I haven't checked youtube, but I did find this very nicely done video on stacking a Chi by a very cute little junior handler!! He does a very nice job. And gives you the basics on what you should be working on.
There are probably many videos on stacking dogs for show on the table, so I bet if you do some research, you can find lots of information.
You should also be working with her on lead. At this age she should be trotting along nicely with you. It's OK if she lags or forges a bit. She doesn't have to be in heel position. But you want her tail UP (very important) and her ears should be up with a very cute and happy expression. When you come back to the judge, she should be alert and show her expression and free stack. All of this you will learn at your conformation classes. I hope you are taking a class with other students, as your dog needs to be very comfortable and socialized with other people and other puppies.
I haven't seen any close up photos of your puppy, but if she has tear staining, since she is white, that will really detract from her, so I'd work with your breeder on getting that cleared up. As for trimming a long coat, I can't help you there. You will need a professional handler or your breeder to help you before you show.
Good luck. Hope this helps!