What's the best race and class to be?

I'm new to the GuildWars world and i've already pre-order Guild Wars2. And i have no clue what race or class i want to be. I'd like some some help, for example what race works best with what class. And since I' know 0 people who are planning on playing this game I was wondering what would be best for soloing. So there is everything in a nut shell, also thanks you to anyone who can guide me in some direction.