doing quest and fighting in the campaign will help level them quickly, I got mine to level 10 by doing the main pack questline plus other exploring stuff.
Adding compainions to your wolves will also make it easier to fight in the campaign and win battles to gain exp for the levels,
You can also do the campaign for each one of the four packs! So if you're stuck on one quest, you can switch to trying a different pack's questline. It won't change your account's pack.
