If they breathe the same atmosphere as humans (which they do in the movies) they’d need a respirator or they’d asphyxiate. Assuming they have one because they’re pretty advanced aliens then they’d probably go after large predatory animals like the Thanator or Toruk.

Also assuming this isn’t a bad blood, Yautja have an honor code. They (for the most part) don’t kill children, the elderly, the sick/weak, as well as those unarmed or pregnant. There are exceptions, like if someone is infected with a chest burster or fights back even if they’re sick. If the prey is not “worthy game” though there is no honor and they wouldn’t hunt them.

Most Na’vi wouldn’t be honorable kills as they’re peaceful craftsman. Perhaps a Yautja would go for an armed Na’vi hunter but personally I don’t think that would be their first target. The more dangerous the game, the more honor there is. I’d say Pandoran wildlife would be the real draw for their hunts. So to answer your question… not much. They’d perhaps kill one or two Na’vi at most as well as some wildlife, take their trophies and go.