Well you can actually play any class but make sure you also level up Conjurer. You can grab raise / cure / shell from the conjurer skills to use on any class while you level it. So i would make your first priority leveling up a conjurer to level 15ish or so to gain access to a couple of their skills then switch to whatever class looks the most interesting to you. While leveling the conjurer up you will prolly also see some other players and maybe get an idea of what you want to play.