There are no classes in Asheron's Call. Character Professions, also known as templates, are available as mere suggestions for starting skills and attributes along with suggested order of acquiring additional skills as the character is leveled. There are many popular character templates, both Turbine and player created. If after creation you discover you made a mistake in selecting your attributes or you just wish to change them, you can adjust them with the Attribute and Skill Redistribution quest once you reach level 25.