I know the feeling. Sometimes you get some really crappy luck, other times, you won't get attacked ever.
Get down south to one of the lower cities, like NCR or San Francisco.. there's a lot less PKs (at least in my experience).
Once you get enough know-how to get a gun, go find some Brahmins around NCR (1 square N, 1 square W), and get yourself 10 brahmin hides to build a tent in the desert, near the mines, preferably.
I'm still new at this myself, and I've struggled at first, but if you get some friends, it'll make things a whole helluva lot easier. There's always someone around that'll be willing to help you.
My name is Luna Blacke in-game, so if you find me, I'd be willing to give you a hand (not that I can do much, except offer a bit of newbie guidance). I'm usually in NCR, or the mine to the southwest of it.
Good luck...hang in there, stranger...
-Luna-