WoW, short for World of Warcraft is a game in which players have the option to battle each other in different kinds of settings. These settings include Arena Games, which are small maps where 2 Arena Teams face eachother in battle. There are 3 Arena Game sizes, one is 2v2(two players versus two players), 3v3 and 5v5. Here you have a rating system, whereas players with less "skill" are placed on low ratings, most often around 1100, and skilled players, around 2000 rating. The more you win, the higher rating you get. If you win against a team that is a lot higher rated than yours, you get a lot more rating. The Arena's only objective is to eliminate the enemy team, whichever team manages to do that, wins.
This type of rating also applies to Rated Battlegrounds, where players face each other in 10v10 or 15v15 battles in regular Battleground maps. Rated Battleground groups, or teams, often have a leader or several which will tell you what to do during these games. You should listen to them, otherwise they might just kick you out! Though if you are new to the game, or just PvP, then I can recommend beginning with regular Battlegrounds.
Regular battlegrounds often consist of leechers and less motivated players, they're good for practice, but often you'll either get close to no competition at all, or way too much competition. Balanced games in these regular Battlegrounds are pretty rare, often one team has way better gear or more skill than the other.
Battlegrounds always have objectives. This objective could be to take an enemy flag from their base and capture it in your own like in Warsong Gulch(WSG), or TP(Twin Peaks), it could also be to capture and hold bases like in Eye Of The Storm and Arathi Basin, could even be to kill a final boss in the enemy base like in Alterac Valley or Isle of Conquest. These objectives even mix with each other in some battlegrounds like Eye Of The Storm.
The best defense is a good offense, that also applies to PvP in World Of Warcraft. Though you also need stats like Resilience and Stamina in order to be a match for the enemy, and able to survive. You should always be active in one way or another, you should never wander around aimlessly. If you're a DPSer, constantly do damage or Crowd Control (Polymorph, Blind, Frost Shock, etc). If you're a Healer, constantly heal targets that are on low HP or CC the enemy as much as you can. Doesn't matter where you are PvPing, you should always have something to do.
If you're dying, go defensive, use all your defensive abilities and attempt to go outside of the line of sight of the enemy, and run towards your team's healer(s). If you don't have any defensive abilities ready, use all your offensive abilities - because like I said earlier, the best defense is a good offense. If you are able to do more damage to the enemy that is attacking you than he is to you, then you will beat him, unless he has more defensive abilities than you.
