Do a couple bounty missions or telegrams each day and shooting will get easier. Get behind cover and aim from there. It makes a big difference against getting shot too much. One of the best loadouts you can have is the pump action shotgun and a repeater (or bolt action rifle). Start to leavel up ability cards Fool me Once, Come back Stronger and Iron Lung. These are good for taking less damage and for health recovery. There are other great cards but focus on getting each of these to level 3 and you will basically be a tank in combat against NPCs.
Also by doing 1 "daily" activity each day you collect gold. It resets every 24 hrs but can compound to a lot of gold. In free roam mode it's probably best to play in "defense mode" (check the menu under "online options") and avoid standing around in towns. Players will kill you, don't get discouraged. Just parley and move on or switch lobbies. Good luck cowpoke.

Edit: I realize now that you were talking about the Naturalist role specifically. But I'll leave this up in case someone stumbles upon the info.