When you create products and assign them to categories, the way those products display on your storefront category pages depends on your theme settings. Every theme in our Theme Store app is a bit different, but they all share elements in common.
To see which settings are available on your theme, access the Store Editor app and select Content. Then, from the top menu, select Category (the default selection is Home). Here, explore your options to define the layout, number of products, number of rows and columns, etc.