All years before 0 are referred to as BCE, or before common era, but since there hadn't been a common era yet, how did people before the year 0 keep dates? Or did they at all?
I apologize for how poorly worded this is, and it's probably a dumb question XD
Not a dumb question at all -- in fact, it gets asked here a lot. Not discouraging further answers, but you may be interested in this section of the FAQ on calendaring, particularly the section on "other dating systems."