(of course this is subject to change with every expansion but things will tend to favor the freep side as the hotfixes come along after them).
First: Play a free person (freep) but know that you are expected to reach max level and acquire a reasonable amount of the better equipment before entering the moors or face the wrath of those who came before you. As far as I know this still requires grouping and running many tedious higher end quests to get said equipment. (I'm guessing that just regular equipment is really fine but you won't be so uber and might die more (a no no in freep land).
Second: If you insist on playing a creep (just takes reaching level 10 on the freep side) be ready to die, a lot. Death is a popular creep trait even for those at the upper end of the scale but that's ok. Creeps are really just entertainment for the darling Turbine favorites "da freeps". (be aware that T is making another effort in upgrading pvp on both sides but as a veteran of 5 years of this kind of thing please don't get your hopes up).
Third: Play a warg as your first creep: please! If only to frustrate the freeps and make it a bit harder to ride around raking in easy kills. Personally, I have always been a fan of the weaver class and have run the gamut from noob to veteran many times and unless they make spiders uberriffic I will continue to play one for the most part. I do like to watch aimless freeps ride around endlessly looking for solo creeps to swat from my burrow.
Follow these 3 things and you will probably have more fun at pvp than you would have otherwise.
Thanks for reading. Mummy R7 (4 times) weaver (the one who can't 1v1 or won't use every buff known to Turbine while playing with 1 audacity because I'm in no hurry to get it.)
Ancient spider of the moors (5 years and counting). I miss Nidor....