I don't have any sales yet, Can I still use Popify?

Yes! 

In case you don't have any orders placed at your shop yet, you can use the recent Add to cart popups in order to show your recent added to cart products or you can use any other popup type like the Communicate type or the Discount popup in order to attract your shop visitors with special promotions and gain more sales.

Once you'll get some sales you can always add the recent orders popups to your shop.