I know this is a noob question
I’m playing on a pvp server, I’m wondering what zones allow you to attack players on the opposite faction. My guess is starting zones but I’m not sure, and what about inside cities?
Example: If I’m a horde would I be able to attack alliance players in Teldrassil, inside Darnassus, and/or Darkshore?
everybody can attack anyone at anytime even your own faction can attack you
hm, so I’m still wondering
Starting zones are not flagged for pvp. So as a horde, you could not go and kill people in teldrassil. I think you might be able to do it though if they attack you first 
so if you can manage to taunt them into attacking you, then you could farm lowbies in teldrassil
Zones that say contested are zones you can pvp. Any opposite faction major city and starting zones are going to be safe for them. They have to attack you or have to be pvp flagged. You can see someone on your own faction is pvp flagged when their names are green, blue names means they are not pvp flagged.
Technically no zone prevents PvP, but the starting zones (the whole zone, not just the 1-6 area) are considered Horde or Alliance territory and will not flag a low level character of that faction. If that character chooses to /flag, though, they are fair game.
Level 1-10 zones, 10-20 zones (or 25 in Barrens) and capital cities you can unflag in even on PvP servers, provided they are your own faction’s.
On PvE servers you can unflag anywhere with the exception of enemy capital cities (i.e. walking in to Orgrimmar as Alliance will flag you even on a PvE server) or sub-zones exclusively dedicated to PvP, such as the Gurubashi arena and BGs.
This was mostly what I was confused about, the level 10-20 zones, thank you