First you should try Silkroad Revolution (Sro-R),International Sro is kinda left by Joymax, so you better go to Sro-R which only got released this week with some
improvements.
So you won't be too far from other players, both are official clients btw if you are wondering.
2nd, there isn't really a thing such as a "best" race, they might not be 100% balanced but they are close enough

Some common Pvp builds are Warrior/cleric [Euro side], Glaiver [Chinese side].
Bows/Crossbows are fun to play with too and got the highest range in the game but you got to carry arrows which can take too much from the inventory.
Each build got their own unique skills, play style, just play a bit with them and find what you like most.
A few things to know are that when adding most of your skill points to
Pure Int = High magical damage/defence, Relatively Low physical damage/defence, Higher overall damage, Low Hp, High amount of Mp, Criticals don't hit for much more than the normal attacks.
Pure Str= High physical damage/defence, Relatively low physical damage/defence, lower overall damage, High hp, Low Mp, Criticals hit for about twice the damage of normal hits.
Well if you can ask more specific questions of what you want to know.
^_^