PVP question

So i have been pve all the way from 70 to 85. I was dw frost pking at the lower levels and did ok. I want to start gearing in pvp. (i know my gear sucks but have to start somewhere) Anyway my question is; do I need to spec my off spec to 2h frost or unholy? It is blood due to me questing a lot to level to 85 but do not like pking as blood. Anything helps, thanks! Also i have never played unholy at all so that maybe taken into consideration. I want to do battlegrounds as well, not so much arena though i will be doing that some.
do research on each. test them out and play what you like. frost and unholy are both fairly competitive when played well, and all 3 specs perform fine in pug bgs.
Of course, Kusari is right. You may want to try them all, but 2 handed frost seems the easiest and most forgiving in pvp and pve for newer dks. Unholy takes a bit of time to get the dps really rolling. If you are doing 5 mans, you will find trash going down so quickly, your true unholy dps will be cut short. You may find a similar situation in pug bgs. You and/or your opponents will not live long enough to really see your damage matter. Arena, rbgs, and raids are places where unholy really shines.

It seems 2 handed frost has a bit more RP regeneration than dual frost, which is helpful starting out. You won't have the survivability unholy has, but this shouldn't matter dpsing 5 mans, and I do well in reg bgs. Frost has a few buttons to spam and is very bursty. Regardless of your choice, you will die a lot in pvp starting out until you get your gear and res. Accept that fact and stay near groups and heals.