Here's a few:
-You can group in Upper Guk.
-You can solo in South Karana. Centaurs don't give faction hits and there's a vendor in the encampment. Most SK mobs are on a 6-7 timer so once you nail a few spawn spots down you should have more than enough stuff to kill. Roaming animals might be aggro, but centaurs and aviaks shouldn't be
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-East Karana has spiders. Tons of spiders. And dogs. All in your level range.
-Runnyeye has an okay xp modifier, but while I got experience with the zone, I don't think you could solo it right now. Too many roamers, too many 2-3 spawn spots and no room for setting up and then space to kite.
A little bit into the 20s you can move on to undead skeletons in Rathe Mountains, the Splitpaw gnolls at the spires and the treants in SK.
If you don't want to stay close to where you are, well there is the giants in Warsliks, the goblins of SolA (<3 xp) and .. forgive me, Mistmoore.