Hi, Maiasaura -
No, the theme does not come with a shopping cart built-in. You would need to do that after installing the theme.
The theme is just a "skin" over WordPress. It's simply designed to look like a classic ecommerce site, and then you would need to add the functionality to make it happen.
There are plenty of good, and free, shopping cart plugins out there for WordPress though. Here's one: http://www.instinct.co.nz/e-commerce/
Lots of people have said this is a good one to use and very user-friendly.