You can easily add a product collection to any page using this element.
How to Use The Product Collection Element
In the right sidebar under "Elements" scroll down until you see the "Collection" element under "BigCommerce" heading.
Then simply drag the element where you would like to place it on your page.
In the right sidebar you can then change what collection is being displayed, the number of columns per row, and the the number of products from the collection displayed.
Note that it is normal for the collection element to not load elements inside of the editor, this will appear correctly on the live page.