Products are published as a collection rather than individually.
To publish your collection (Step 3), you need to click Back from the Prices & Edit screen to return to the main view. The Publish Products button will appear in the top right corner.
If you only want to publish one product, you still have to go Back. Before you publish, toggle off 'Everything Enabled' on the right hand side. Then toggle on 'Enabled' for just the product you want to publish.