Can I add Navigation to my Hyundai Sonata SE 2016? I was wondering if there s just something I can purchase to download or something?

Not to the Hyundai factory head unit if that is what you were hoping. You'd have to purchase an aftermarket external Navi system.

Buy a portable GPS unit. I have a Garmin Nuvi I can use in any car I drive and carry in my coat pocket. It comes with lifetime map updates I can do myself on the computer instead of needing it done by the dealer, costing $$$$ on an OEM in-dash model. Smartphones will often act as GPS when that application in installed. If you have a smartphone, you probably already have GPS and don't need to buy anything.

There are several brands of relatively inexpensive (under $200) portable GPS navigation devices that just plug in to your car's auxiliary power outlet/cigarette lighter socket. OR you can just download a navigation app to your smart phone. Garmin is one of my favorites...

https://buy.garmin.com/en-US/US/cOnTheRoad-cAutomo...

Get a nav unit installed at a car accessory shop.