Where can I file for divorce - in the county that I was married in or the specific city?

The city that your marriage took place in does not matter when filing for a divorce.  As long as you meet residency requirements (they vary based on the grounds claimed), VA has counties that govern which court your divorce will take place in.  This is called "venue". You can file suit in the county where you last lived together as husband and wife, in the county where the defendant resides if he or she is still a resident of the state, or in the county where you reside if the defendant is a nonresident.

Note: Be careful that you file in the appropriate county or the court may transfer your case to the appropriate jurisdiction at your expense (not to mention time).