Gather Silverleaf, Peacebloom, and Mageroyal in the Newbie zones (Durotaur, Mulgore, or Trisfall Glade). Once you get to around level 75 (which you should be able to get without any problems in the Newbie zones), move on to either The Barrens or Silverpine Forest to collect Briarthorn and Bruiseweed. That should get you on your way to catching up with your level. At level 33, you should be around 200 Herbalism, which will let you gather Wild Steelbloom, Liferoot, Goldthorn, Fadeleaf, and Khadigar's Whiskers (all of which can be found in Stranglethorn Vale).