Hello,
It's nice to see some new members. I hope you will learn alot from the forum as well as from my blogs linked to from the home page of ballpythonplanet.com.
If the pet store was competent the could have done what is called popping. This method is most acuate when determining the sex of a juvinile snake. It's best done by someone how knows how to do it, but it is not hard to learn how to. There is an excellent video on ball pythons by Collete and Dan Southerland. It's very informative and you can learn alot from it. They show in great detail the proper way to pop a snake. If you cannot afford the video you can find a few sites that explain the procedure.
As for what to do about trying to feed your new baby fuzzies. There are a few things you can try.
1. If possible rub a fuzzy mouse with a pinkie.
2. Leave the fuzzy in a tub with a lid in with your snake for a while.
3. Wait it out, your baby will get hungry and eat when it is ready.
Snake can go for a long time without eating. It is not uncommon to have one go for a few months at a time. If you can help it they should eat once every seven days to two weeks.
If you have any other questions feel free to ask here on the forum in the questions topic.
Eric Rovegno