PvP - build basics
First things first, the pvp builds are best accessed from the PvP lobby, because there are merchants and testing golems, and certain skills are game mode dependent, so you want to look at the right version of the skill.
Next, make sure you're looking at your PvP gear, which consists of Amulet, Relic, Rune, Weapons, and Sigils. This is accessed by clicking the toggle to the right of your helmet in the Hero Panel.
"What build should I play?"
Well, I'm not a build curator, but metabattle has good builds, for multiple game modes too. They're the go-to resource for builds for PvP and WvW, with useful mini-guides. Once you grab a build from there (in the "meta" or "great" section to start with) - take it over to a golem ([&BNkJAAA=]) and start practicing some of the combos being laid out in the metabattle guide, if there is one. Get comfortable with these combos until they come naturally. Repetition legitimizes. Then you can move on to the NPCs, and practice combos there while not dying. Ideally when playing a build the mechanics of it will be second nature so you can focus on the rest of the game, and how to win it. After you feel comfortable with the NPCs, I'd then take the build to unranked, where once again, repetition legitimizes. Nobody ought to care about you throwing off the face of the planet (and if they do, block them, lol). I'd recommend ~10 games for a new build to get some idea of what's going on. After that, you can decide when you're ready for ranked.
Some notes on build crafting
A good build implements a lot of different things. Here's a quick list of things to not forget if you decided to down the rabbit hole.- Stunbreak(s)
- Condition cleanse
- A way to win fights or nodes
- Mobility tools (swiftness, dashes)
- Active defensives (invulns, stealths, ports, mobility to an extent)