Very Basic Setup Question

So I im using iproduct templatic theme, and the eshop plugin. I already have “buy” buttons setup with the theme. I dont get how to setup the acually products and buying process. Like once the click the buy link how do I associate that with a product and add it to the cart. my website is thatguyon.com if ya wanna take a look. Is the a product database creation part and then once I create my product how to i create a link so that when they hit buy now itll add that specific product to the cart?