The "Shipping Origin" would be the location from which your packages would be sent, whereas your "Shipping Zones" are the countries that you'd be shipping to. Since you're dropshipping, you wouldn't need to worry about inputting your suppliers' shipping address into the shipping origin section as this area wouldn't be used for your business model. That said, your Shipping Zones would hold your individual shipping rates which would be created based on the countries you'll offer your products to.
Since you're using epacket, you'd need to look into creating either price based, or weight based manual shipping rates for your store. This will allow you to charge a flat rate shipping fee which would be determined on either the total cost or the total weight of your customers' cart. For this, I'd recommend reviewing Oberlo's help document "How to Set Shipping Settings" as this should help clear up any questions you have surrounding your shipping area.
Let me know if you run into any questions along the way!