All the products available on nop-payments.com are digital downloads. Therefore, no shipping is required.
The products can be downloaded right after completing an order (either paid or free) by going to the orders' details page on nop-payments.com.
You should also receive an e-mail notification, no more than a few minutes after you place your order, which will contain a note with your ordered plugin.
You can see a list of your orders' notes, by visiting each order's detail page, and you can download the plugin(s) later on.