Keep drinking water from the fountains. And no, do not eat radroach meat. Save it for when you get outside of Vault 101, because it's hard to find stimpaks. I never got over 40 stimpaks until level 30. If you don't want to waste your time looking for stimpaks in mailboxes or you don't want to waste money to get healed from the guy in Megaton, then set one of your tag skills to explosives. After that, disarm the bomb in Megaton (Do not request caps as a reward, because when you disarm it you'll get keys to a free house.), then after you get the house, you have a bed to sleep in. When you go to sleep, always set it to 6-8 hours. It gives you Well Rested (Extra EXP.)