More inventory space
You need to make your way to the east part of the ravine, killing the bristleback quilboars that drop the belts for your quest and more of the battleboars. The Chief lives in a tent on the east side of the ravine. When you get out of the tunnel entrance and in to the ravine keep heading east up over the hill, killing quilboars as you go. Somewhere along the way you should reach level 4. Don't worry about going back to your trainer yet though, just keep killing.
If you are lucky you may find that the quilboars drop pouches for you to use. Drag any pouches you get to your equip container bar on the bottom right of the screen. This will mean that you can carry more. You can also setup a key to open up all your backpacks at once. To do this hit Escape and click the Key Binding button and scroll down about half way until you see the Open All Bags option. I have this bound to my I key.
Along the way you may end up running out of room in your backpack. You could go back to camp and sell loot to make room but that takes time and I prefer to juggle the loot I get, keeping the items I think will sell for more. Generally the items with the better stats will get you more.
Eventually you will come across the hut where the chief lives. He is inside and surrounded by loads of his mates. To get to him you will need to clear a path. Before we do that there is another quest we can pick up. To the south of the chiefs hut you will see a hill with a cave at the end. This is where you want to head to.
Spell casting monsters
You will encounter your first spell casting enemy on the way to the cave. Like you, these Bristleback Shaman will cast damage spells at you from a distance. Use the same tactic as before with these guys except you may have to run up to them once you have cast your three wrath spells to finish them off.
A monster with a name
Once you get to the cave you will find Squealer Thornmantle, who is guarded by at least one of his friends. You need to take both of these guys out at once. This is good practise because taking on multiple enemies at once will be something you have to do a lot in the future.
For me, the best tactic is to concentrate on the higher level enemy first. He will be able to do more damage, so you want to take him out of the picture first. Then take out the second enemy. You may need to use your heal spell during the fight, so be on your toes. Some players might like to take out the weaker opponent first because he will go down quicker. Try out both techniques when you can and find the one that suits you best.