Difference between sPvP and WvW
In both types of PvP, all players are automatically set to L80. Structured PvP or sPvP for short is your traditional PvP maps that you might be familiar with in other MMOs. You are given all the skills and all the PvP gear you possibly need so that everyone starts out in even grounds. It is a pure skill based PvP without any gear gap or grind. You can access sPvP by going to Hall of Memories (last tab of your Hero window opened by pressing the H button).
Once you are there, look for the PvP browser NPC.
Talking to the NPC will open up a window with a list of servers, you can either press Play Now to join a random server or chose a server and click on Join Game.
You do not earn XP while doing sPvP, you earn Glory instead, which can be used to purchase better looking (but not better stats) PvP armor.
World vs World or WvW is a more open form PvP that focuses on capturing and defending keeps and towers. All players are set to L80 but you will wear your own gear and only have access to the skills that you have unlocked. It is therefore recommended that you do not jump into WvW right away and instead level up in PvE a bit to unlock some skills.
To access WvW, you will need to find the portal to Lion’s Arch in the Hall of Memories.
Once you are in Lion’s Arch, each of the Asura gates next to you will lead you to different WvW maps (Borderlands, Eternal Battlegrounds).
You will earn XP while doing WvW and there are also high level crafting materials that you can gather as well.
Glory is as type of accountwide currency you earn while doing structured PvP. Earning Glory will allow you to increase your PvP rank and purchase new PvP gear that give you better looks. The first 10 ranks will require 500 glory to reach.
SWITCHING TO DIFFERENT WEAPONS FOR SPVP
When you port to Hall of Memories, you are given two weapons by default but they are probably not the most ideal weapons for you. Luckily, you can get other weapons and re-rune/sigil your armor/weapons by going to the PvP vendor to the right of entrance in Hall of Memories. All of the PvP weapons, armor, sigils and runes are free but they can be only used in sPvP.