Well, Basically every class has a propose in the game. They all have a valued position to be played. Some people prefer the role of a healer some a tank. While others play a more spell casting type of character like a mage or ranged damage per second = Rpds. Everyone playing there proper roles will allow the group to function properly.
In the Eternion world things can be different than in world of warcraft as far as game play gos. Carefully read the skills and abilities of every race and class before you make your final pick. Alot of races have perks that allow you to play a certain class with an advantage.
So as you create your first character ask yourself what you would like to be in the game.