I'll be getting into World of Warcraft soon and I think I'll go warrior. I've been looking into the playing style i'll most probably adapt to and was wondering what was better for a warrior. A 2H Weapon or Dual wielding. (In general, meaning PvP and PvE)

The only classes you usually see dual wielding are rogues and enhancement shammy's. Warriors are all about pounding people in the face for gigantic amounts of dmg. I would go 2h. Or if you want to get into dungeons instantly, go protection with a 1h and shield. Great way to get loot throughout the game.

For PvP, you will want to use a 2H Weapon probably with Arms or Fury in the Talent Tree. Fury at a point can use Dual-wield.

For PvE, I would recommend Prot in the Talent Tree (Using a 1H and Shield). Survival is very high and damage done is Good. Plus finding parties for Random Dungeons is easy. I would advise caution. Some players hate new players. Place them on ignore if needed. There are nice players in town that can probably offer some advice as well. It just takes time to find them sometimes.

2h. It is usually hard to find good swords/axes to dual wield at low levels. Its better to DW at higher levels.

It really depends on what stats you want to work with. Warriors, moore often than not, have above average amounts of health so you're primary concern is going to be close range combat. BUT, if you plan on focusing on fast attacks, moving around enemies, gaining combat advantage, and generally being a powerful pest, duel wielding is for you. On the other hand you can get a very large, two handed weapon and go smash peoples face in.

Honestly, of the two, the warrior is more easily set up for face smashing. If you want to duel wield go rogue. Warriors are meant for killing and breaking with overwhelming force and a two handed weapon or a sword/shield combo is best for you.

These general rules are similar, if noot identical, for all RPGs, MMOs and stuff like that.