Yeah, a hunting rifle seems to be my major weapon for much of the time.
Keep collecting gunpowder and lead scrap when you see it and with a tinkerer workshop you can craft your own ammo. There's a tinkerer workbench in Flatwoods. As for radiation, you're not going to be completely radiation free, its really just trying to manage it, so it doesn't impact too negatively.
Here's what works for me - I got/used the cannibal perk card, that way you can eat the NPCs after you kill them (ghouls/scorch/super mutis) - sounds gross typing it I know, but it means you don't need to carry or worry about food. I also set up my camp near a river and I have a water purifier, so that takes care of my water needs. With food and water taken care of, the next thing is find scrap for weapons repair, and I just take anything and everything when I see it.
Also keep an eye on weapon levels, that is a level 15 hunting rifle is going to do more damage than a level 1 hunting rifle. They look the same, just one does more damage. So in other words, don't ignore an opponent's weapon just because you already have it - it may be a higher level. Scrap your junk whenever you can, it saves on weight
My issue right now is stimpacks, I only have about 8 of them, I've run into a bad streak of luck and my supply is low, the next chance I play I may see how I can craft them if possible.
I'm at the quest of The Missing Link where you need to do a bunch of stuff at Top of the World location, prior to the wasterlander's DLC that place was empty, now there seems to be raiders and I've not started the questline for that, so I'm a little hesitant to just dive into that location.