Go to Store >> Store Inventory, and click on the "drag & drop to reorder" icon that you'll find on the right-hand side of the product you wish to change. Then simply move it up or down until you're happy is in the right order. Repeat the same steps for each product you wish to change:
For this example, 'Hoodie' will be the first product shown on the customer-facing site:
Jump to:
The Store/Shop