Now before you choose a class, you must first choose a race. There are 3 races:
Asura||Gaia||Deva
Each are unique in their own ways. I'll introduce you, briefly to each race. Once you're done, you can move onto the Classes section.
According to Rappelz background, the Asura race is one of the two races of gods that descended upon the Rappelz world. Asuras are the "Dark" class of the game, represented with purple, black, and other dark-ish colors. They usually use Shade magic and excel in speed, agility, evasion, and quick strikes. The theory behind it is, hit them fast, hit them hard.
Their home is Katan, the City of Darkness.
Gaia are the "human" class. They work in conjunction with nature and are represented by earthy colors like brown, red, orange, and yellow. They use all kinds of natural magics such as Earth, Water, Air, and Fire magics to complete their tasks. They are a good fusion of the two other races having a good balance of durability and strength.
Their home is Horizen, the City of Humans.
The Devas are the other class of gods, characterized by Light magic and the color white and blue. They rely on a lot of holy magic in order to achieve their goal. The Devas excel in durability, having some of the most defensive classes in the game. Almost all, if not all of them, classes in the Deva race have high defense and high HP.
Their home is Laksy, City in the Sky.