Hi,
Been showing for a while now myself in both open and champ shows. It is very confusing at the beginning but you will get there.
I'd say enter the puppy class in her breed. You normally cant enter the any variety classes if you havent entered the breed class or the class for your group (toy group in your case) which is for dogs that dont have seperate breed classes of their own (also known as AV Toy NSC not seperately classified)
the Any variety classes such as Any Variety puppy, novice and special beginners, if they are being held are usual good. However they are usually held at the end of the day so you shall have to wait around for them.
As posted earlier if your pup wins her puppy class in her breed and then wins best puppy in breed, i would suggest you pull out of the any variety classes so you dont scupper your chances of going in for best puppy in group or if you are lucky enough
best puppy in show.
Most importantly have fun and dont worry about it!! It is your first show after all.
Good Luck