You should be able to get the Megaton house (w/ bed) if you raise explosives to 25. At that point, you can disarm the bomb in the middle of town. I think you need to speak with the sheriff first, then again after disarming. Quite a few things like that where you'll need a certain skill/skill number to do certain tasks.

The game gets a bit easier after learning the targeting system and allocating the stat/skill points/perks in relation to the type of character you'd like to play. Fast Travel makes getting from place to place easier too, if you've visited prior.

It's a bit tough at the beginning to do some of those quests since the further you travel out, the more things you can run into. I think there was a school nearby that had a few Raiders but was a decent place to find loot, caps, ammo, weapons, and exp.. There should also be a super-market near Grayditch (fire ants) that had the same.