In addition to a race and a class, every character has a background - this is what you were doing before being an adventurer, or in between going on adventures. There's lots more options than just these; these are just the ones that I think will play into the campaign. Ask me if you're really keen to be a Hermit or an Outlander; generally, these are the more urban, working-class options.
Acolyte: You're part of the clergy, probably for the Sovereign Host.
Charlatan: You're a trickster and huckster in Sharn.
City Watch: You're a member of Sharn's notoriously corrupt City Watch.
Criminal: You're part of one of the criminal gangs in Sharn.
Entertainer: You're a performer or entertainer in Sharn. You might be an actor, musician, singer, or something else.
Folk Hero: You're famous for sticking up for your people during the Last War.
Gambler: You take part in illegal underworld gambling in Sharn.
Gladiator: You take part in the underworld pit fights in Sharn.
Guild Agent: You work for the Clifftop Adventurers' Guild in Sharn. Professionalism and competence are your by-words.
House Agent: You're a member of one of the Dragonmarked Houses, or you work for them. (Due to the disparate nature of the Houses, this might also be represented with a specific background, e.g. Guild Artisan for House Cannith, etc.)
Investigator: You're an inquisitive, or private investigator.
Mercenary Veteran: You were part of a mercenary company during the Last War.
Newspaper Journalist: You're trying to find the next big story for the
Sharn Inquisitive, the
Korranberg Chronicle, or another.
Refugee: You find yourself displaced as a result of the war, and are now living in Sharn. Ideal for Cyrans or even for Warforged.
Sage: You work for Morgrave University, the largest centre of education in Sharn.
Soldier: You enlisted and took part in fighting during the Last War.
Spy: You were a spy during the Last War.
Urban Bounty Hunter: You're an inquisitive, or private investigator, working in Sharn.
Urchin: You grew up on the streets of Sharn.