Level whatever you feel like playing, it doesn't matter whatsoever because..
During leveling, you will encounter equally skilled players, with the same mentality, expectations etc.. and you will 'click' with them, if you allow yourself to and are a social person. Those are the players who you will be spending most of your time with in dungeons and on harder quests. Later on, you will join a guild and find hopefully other same-minded people and so on.
Person's social aspect is the key, as long as your are positive there, nothing can stop you and you will do well. You'll encounter many rubbish players on the way, maybe skilled but constantly whining, bitching, moaning, just ignore those and move on. My list is quite long, for example xD