Hey OP. Sorry you're having a bad time (like, seriously, not being a booger here). This game takes a slightly different approach to thing than previous iterations, so some adjustment is needed.
I've been playing on Very Hard, so any tips should translate to normal. And these are for a 3 endurance character, so I'm not just tanking all the things.
First, be prepared to run away. Leaving is TOTALLY an option. Especially at low levels, getting jumped by a powerful mob or teamed up on by raiders is deadly.
Second, if you aren't sure you are safe, sneak everywhere. This not only keeps you from being immediately target, but gives you an "Early Warning" of sorts with the stealth monitor. Once it goes to "Caution" you can see enemies on your compass.
The above, mind you, is a HUGE deviation from FO3 and New Vegas. In those, enemies and NPCs would automatically appear on your compass at a range determined by your Perception score. No more.
Third, don't engage Super Mutants, Yao Guai, or Deathclaws until you are level 12-15 at least. They hurt a lot now. Sneak away.
Fourth, pick a weapon "type", and keep up on damage perks for it. The new "types" appear to be one-handed non-automatic, two-handed non-automatic, automatic, and melee. Focusing on one lets you get more capable quicker. You can always go back and level up alternate combat styles later on when you have spare perks.
FInally, keep up on appropriate crafting perks for both your chosen weapons AND your armor. For ranged weapons, this is Gun Nut and Science. For melee weapons, it is Blacksmith. Armor is Armorer. These let you make your weapons WORLDS more viable.
It's a great game, and you'll get there. Just take your time, enjoy the setting, and try not to get shot too much. 