Ryzen 7 5800x or 5800x3d?

I have an old pc with a RTx 2060 6gb, and a Ryzen 5 3600xt and a 16 GB Ram ddr4. I would like to buy a new processor (I'm new to the PC world so tell me if I should do something else) I premise that I use my pc only to play story games, I don't touch any competitive multiplayer games. I didn't really get what's the difference between the two CPUs other than the price. I'm in Italia and I don't really know how much I'm gonna spend