Your customers might not see products because they may be in Draft status. Products become visible and available for purchase once they have been set Active in Shopify.
You can also check that your products have been synced by navigating to the Connection Tools section and selecting Edit on your application record. Inside the Product List select the + Add Products or + Add Packs buttons to sync the new products or packs to your Shopify store as draft products.
If your products are showing as "Out-of-Stock", you will need to setup a shipping profile.