Okay, good question. You want to WvW, but you don’t know where to start. Here is a quick rundown:
First, you need to be connected to your teammates to understand what your team is doing so you can play with them as a team. You can find your server’s community website here and you should log on to your server’s voip server so you can talk with your teammates. Guild Wars 2 has large and friendly communities, so don’t be afraid to jump in and talk. You can find good builds, advice, and immediate help if you ask!
Second, you need to have a good hotkey setup and appropriate graphics settings. In order to have the smoothest gameplay possible, you should try to get the highest framerate possible and still enjoy the graphics. I highly suggest turning off shadows, reflections, and lowering the Character Model Quality and Character Model Limit to a good level. You will need to restart the zone or go to another zone to change Character Model Quality. If you wish to use a WvW overlay, then you will need to play on Windowed Fullscreen mode. Uncheck LOD in the bottom left hand corner of graphics options to guarantee that you will see friendly water fields and other important spells.
Third, you will need gear and traits for the role you want to play. Generally speaking, if you are doing small group or solo play then you can gear yourself like you would for sPvP in that you want to do high direct damage with good solo survivability. If you are gearing for more than small group combat, then you need entirely different traits and gear as well as utilities. Large group combat demands high aoe damage and smart survivability. Expert players can survive even with high dps gear, but newbies should start with gear they can survive in like pvt gear or dire gear etc. You also need appropriate food and oil/sharpening stones/crystals for buffing yourself.
Fourth, you will need to learn your class role in a group play environment. Your class role may change depending on what weapon you choose to use. For example, an elementalist using daggers will be a frontline spike damage dealer, and an elementalist using staff might be a support and aoe damage. If you are dying a lot, then try changing your playstyle and look at where and why you died and what you can do to prevent it.
Fifth, you need to learn good decision making. That means you have to be aware where the enemy groups are and where you are and what your group is doing. Communicating on the map can mean the difference between good and bad results. This is why you should always be connected on teampspeak or ventrilo or whatever your guild/server uses. You also need to be aware of supply management on the map and what it means.
Sixth, you must learn what the commander is talking about. See the terminology page for some help, but every server has some differences in language and slang. Try to focus on where you are and where the commander is in the heat of battle, you should never get too far from the commander in battle. The best way to learn what is going on is by getting in the game and playing well.
Seventh, do not give up. If you die horribly, then dust yourself off and improve. You can give up if you want, but no one will take your place that has your brain and your set of skills.