Who'd win?
Let's say they have their basic equipment and appear in a jungle that is neither Pandora, nor Yautja Prime. The predator is experienced, has wrist blades and shoulder cannon (but obviously he will not use it immediately).
The Na'vi is also an experienced warrior, has bow and poisoned arrows, knife and an ikran.
But you can "let imagination go wild" and think of different scenarios, including other combinations of weapons.
Yautja are around 7-8 feet tall and weigh around 520 pounds in armour. Na'vi are around 10 feet tall and weigh approximately 350 pounds. Both are a lot stronger and faster than humans. Not sure about Na'vis, but Yautja are much more resilient than humans.
So who'd win according to you?
I'd go with the Pred :)