PvE is the best way to start, youll gain a huge amount of experiance with out having been yelled at for being new to the game.
Unlocking skills is faster and easier in pve and that helps to build a good pvp char.
As for what kind of char to make for pvp, a monk will get you into teams fast and easy but they are lots of work and get blamed for any mistakes they make. A war is easy but can be ineffective without the right skills.
Mesmers and Eles have great builds, that means there in demand and usualy killed first in most pvp matches.
I would sugest a Necromancer would be a great place to start pvp with. They have good skill balance, self healing, nice offence, tend to attract less attention on the battle field and are not that complicated to learn.
In the end you'll probable try everything untill you find a proffesion and play style that keeps you having fun.