I sorta went through the same thing, years ago- I bought my first horse, and when the day came that I had to put her on a trailer- it occurred to me that, gee, I had no idea how she'd take to being put on a trailer and taken somewhere! She was a flighty, spooky arab and I had never loaded a horse onto a trailer before!
Fortunately it worked out ok for us, she turned out to be fine with trailers.
The best advice I can give you is, if you're not used to leading horses onto trailers, have someone else, who is experienced with loading horses onto trailers, do it for you the first time- then if she turns out to be fine with it, you can do it yourself in the future with confidence.
The biggest thing is, you must be confident! Lead her onto the trailer like you have no doubt she will follow- don't hesitate, don't look back at her, just walk into the trailer. I like to have hay waiting in the trailer, and I also often give a cookie or other reward once on the trailer just to continually reinforce the idea that the trailer is a nice place to be.
As for boots- if she's going to be sharing the trailer with other horses, definitely put the shipping boots on her. If she's going to be in there alone, I would just put boots on the fronts, to prevent her from accidentally stepping on her own heels if the driver had to slam on brakes.
I don't like to use polo wraps in the trailer for several reasons- first, they tend to be more snug than shipping boots, especially if improperly applied, I don't like making my horses wear polo wraps unless for a specific purpose while being worked/ridden.
Second- if a polo wrap came unstuck and started coming off in a trailer, it could be disastrous. Think about all the horrible things that could result from the loose end of a polo wrap getting caught on something, or stuck under a hoof, if the horse tried to take a step to keep her balance and the polo wrap was caught, she could fall down in the trailer. You can imagine the consequences of that kind of accident, especially in a trailer with other horses.
Use the shipping boots.
If you'd like to practice loading/unloading before the big day, that might help. Make sure only to use a trailer that is hitched securely to a towing vehicle- loading a horse into a parked, unhitched trailer, even a big one, can tip the trailer back and cause a disaster. Use treats to reward the horse for entering the trailer, and let her get back off the trailer fairly quickly.
Good luck- I'm sure you'll be fine. The majority of horses handle trailering just fine.