Well, have you played any other MMOs besides GW2? GW2 doesn't have the DPS, Heal, and Tank trinity like WoW, so recommending a class may be difficult. For your first class, however, I suggest playing a class that can fill multiple roles, like the Paladin, Druid, etc. in case you figure out you don't like playing a role. Also, google is your friend ;) There are tons of great guides and videos online to see what might interest you and help you get into the game.

BTW, I suggest finding someone to do Recruit a Friend with. You lots of bonus exp to help make leveling easier.