The product of an alchemical experiment gone right, and later orphaned by an alchemical experiment gone wrong, halflings were created as the perfect homonculi. A halfling lives to serve, and left alone with no guidance, will tend to find an end without objectives to follow.
Communities of halflings can be found anywhere jobs need doing, be it a veritable colony in one district of a city, or in smaller camps by a wizardry school. While they tend to stick to their workplaces most of their lives, some halflings are commissioned for tasks involving travel, almost always involving accompaniment by travelers of other races.
Every now and then, a halfling comes along with a bit more free will and wanderlust, or just disdain for the work they’ve been tasked with, and will strike out on their own. However, such free spirits are considered fugitive, and most citizens will seek to return a drifting halfling to his home, for his own good.
Halflings are basically a slave race, so throw that whole “jolly hobbits on the riverside” nonsense from the PHB right out. They’re okay with it, for the most part, but if you’re playing a halfling, regardless of class, you’re going to have papers. Any halfling players will need to figure out who they’re working for (feel free to make up an NPC for this, we’ll talk), or a cover story for their fugitive status (and who might be looking to get them back).