A lot of players took a few swings to get their characters right. You might find that that first mage you rolled doesn't really synch with your desire to stab an Ogre with that sword. That Human might have been a bit bland for a game where you could be a goat with face tentacles from space, or a walking slab of USDA-approved beef. I know several people who started playing at the bequest of their friends, made a character, leveled it for a while, only to get the message: "I'm sorry, but your friends are on another server!" It can be a bit jarring, especially if you've leveled into the 40s or 50s when a sizable time investment has been made, but perhaps not enough to justify paying for a server or faction transfer. Mistaken class choices can only be rerolled.
I lucked out. My friend who got me into WoW told me exactly which server and faction to start on before I downloaded the trial account. I picked a Human paladin because I loved paladins in Diablo 2 and started on my voyage. The ability to tank fed into my natural tendency to melee things, and sword and shield has always been my favorite aesthetic weapon choice. Others in my guild were less fortunate. Our mage, who played a paladin in beta, rolled a paladin on live servers, only to find that it was completely different than the class he fell in love with in the beta test. He traipsed through a rogue, priest, and hunter before he got around to maining his mage. Our Draenei enhance shaman started out as a Blood Elf paladin who didn't make it past level 40.
How about you? Is your main your first toon?