Fastest way to level?

[Extunarian]

Your best bet is to make the character you like most. If you simply want a character that well XP the fastest, then I suppose a Halfling warrior would be good. Unless of course you group, in which case your bonus and other members' penalties would be shared.

A warrior is a fun class to play, but can be tough, and you may want to forget about the XP penalty altogether and just roll a class with a lot of utility, i.e. a druid, until you get a good handle on the game.