Hey there, sorry for a bit of a delayed response. So pvp in this game is about to get a lot better. Before I get to that, ill discuss the two current formats and what they're all about.
Structured pvp - has tournaments that can be played, although I've never participated. In this format everyone is evened out. You have access to every weapon/skill and armor. This means that the winner is determined by skill, and teamwork. This format is 5v5. There are a couple rotations of what they call conquest maps. Essentially there are points (a, b, c) and you have to take them and hold them. This is your primary way to score points in the match, along with killing other players.
World versus World - I almost exclusively focus on this game mode. The ranking system is based on your server and how your server does overall. So you fall in a tier, and can place within that tier. Moving up and down the ladder as your server does well/poorly. Idea of this game mode is there are towers/supply camps/keeps and in one instance a castle. Your army must take these and hold them to gain points. Currently the meta is to zerg and take the points with little focus on defending anything except your closest towers/main keep. There are siege weapons including trebuchet, catapults, rams, and even golems to attack castles. The war is fought for 2 week periods, with 3 servers. So 1v1v1. The battles that come from this are literally the most epic thing I have ever been involved in in gaming.
This is about to get even better: The sale is because they're getting ready for their first expansion. In this expansion they will be adding a pvp game mode called stronghold. I highly encourage you to watch a gameplay video. The general idea is each side has two gates one outer one inner then a guild lord. You must use supply you fight over in the middle of the map to summon creeps sorta like a moba. You summon doorbreakers and archers. You break the doors down and kill the lord to win. This is going to have an in game ladder, and ways to play as a guild group with a bit more recognition.
WvW they are adding a new borderland map. They haven't given us much info aside from their goal is to make defense a heavy focus. They've said that holding towers around keeps will become much more important to provide choke points and advantages. One advantage they've quoted is that if you hold the proper points around the earth keep, the keep will teraform/move land around to defend itself. We haven't seen this in action so not 100% sure what they mean.
Hope my seriously long description helps. Please let me know if you have any questions. If you decide to get the game I play east coast us around 6pm-10pm. In game name Lifaen The Forsaken