Everything kills you in 1-2 hits at level 1. What are you spec'd? And are you one of those people that likes to 'roleplay' the game instead of treating it like a video game? Because if that's the case then our experience with the game is going to be completely different. As Prime (lol I said Mesh..) said, just run backwards and shoot it in the face. Unless you're roleplaying a Warrior with low str who never runs from enemies... :P
Funny, it really is like we're playing a completely different game, except I'm not really Role Playing. I actually go for a more balanced build with a focus on INT. I don't really remember my base stats since I've modified them with both perks and implants, but my lowest stat was 4 AGI. Strength and Endurance were at 6 and Intelligence was at 8. INT gives you more skillpoints when you level up, and for me that's very important. Plus you get that perk that gives you 2 extra and by the time you hit 30 you get 100+ extra skillpoints than if you went at 5 INT and no perk.
Anyway, about running and shooting, you don't think I tried that strategy? Their DT is too high to damage them with the weapons you have at the beginning of the game. Let alone, if it did work, I wouldn't have enough ammo to kill them. Besides that, I also use a melee build. Later on, melee/unarmed builds are ridiculously broken (ignore 15 DT from everything!) and I'm regretting it. When I play again I'm going to use a more gun based build, they're more balanced.
But what's wrong with people who Roleplay? It's a different, even more consistent, way of playing the game. I don't really do it myself, but I think it's a perfectly valid way to play.
EDIT: Very late edit, but about my above comment on Charlie and the NRC quest up there. Apparently mine glitched and some (not all) people are able to get it to complete if you do the scenes with Ranger Andy. Other people (including myself and my friend) get locked out of finishing the quest. So if you want to completely avoid the problem, do the NCR quest first. You can also risk it and possibly encounter a bug later on in the quest.