two questions you need to ask yourself is:

Do I want damage or play support or tank? I started this game about 4 days ago (I also played the trial on steam but because I couldn't transfer my character to SE version I started over. I was max level for the trial version). I find healers and tanks, especially for those duty (its like a dungeon/party battle) hard to come by. I play as an archer and waited over 1 hour just to get into a quest related dungeon (this is a story quest dungeon).

After you pick your main role. (you could always change it after level 15? Not sure if it was 15.) Next is your class. Do you want to do melee dps? magic dps? support healer? etc. . . You could get to know the other classes better. I believe there's a wiki somewhere that will tell you everything about the class.

There isn't a noob friendly class but I'm not saying there isn't one. Its more of what you enjoy playing which in result makes it easy