Hi Angela
We don't have a default file to pre-populate the catalog. However, you can login to our demo site as Store Administrator (the user/pwd is on the Login page) and you can see how some of the demo products are being setup.
Please make sure to search through the Users manual for examples of how to setup products. For everything else, feel free to ask your questions here. Here are a few interesting topics from the Users manual:
How to install
How to create a simple product