Nah, so there's definitely some wiggle room depending where you are, but most people do lvl 5 in newbie zone and then depending if you've got orc camps or skeletons or lizardmen camps etc, going to 10-11ish. At 11 you can do Unrest graveyard.
There are obviously MULTIPLE places to level. Oasis crocs are amazing lvl 9-17ish. Best quality of life camp. The problem is they don't drop loot. So good luck buying your spells/gearing there. Upper Guk is an excellent place for loot/exp, but CC is a must. Mobs run early and often, social aggro is a problem, and mobs heal/nuke through walls all the time. The exp modifier there is really good though. It can take you to lvl 30 there fairly easily at which point you just go into Lower Guk.
Lavastorm is mostly a thing of the past. Boxers and soloers maybe, but it's not a worthwhile place to be anymore. Same can be said for places like Highhold Pass and Highhold Keep. I went in HHP earlier to check the camps and they really fucked that place up. 7ish minute spawns are good, but there's not nearly enough mobs to keep pace with a full group.
Could also go into Sol A around lvl 20ish and work your way up to Sol B and basically do all of 20-50 in those two zones alone if you can stand it.