Adding a store product to a page is much like adding a module to a page.
First, go to the Page Editor and click on the page that you want to add the product to.
Once the page is open, scroll to the bottom to the "Add & Arrange Modules" section.
Click on the "Ecommerce" option ont he left hand side. All of your product categories will then appear.
Click on the product category you want. Then click on the small arrow in the center of the boxes to move the product category into the right side box.
Then, use the small arrows on the far right to move the category into the position you want. Most often, it should go in the "middle" position.
When you are finished, save the page.