Health is tied directly to strength. Each body part, e.g left arm, right arm, head etc has a HP value. with 8str it’ll be about 80ish. If a limb gets dropped to 0hp it’s effectively broken, aka you won’t be able to use that limb until you get to a hospital. then again, I think someone put in craftable splints and crutches awhile back. Sleeping is generally one of the easiest ways to heal up, although for severe damage you’ll need bandages or first aid kits as well.
Normal zombie attacks don’t actually do enough damage to be a threat except in numbers, but pain and infection are the problem, as a lot of pain slows you down and bite infection can be fatal if you don’t clean it up fast. Of course, there are other things that can be much more of a threat.
As for a starting build, go into options and give yourself some more starting points and optionally increase the amount of trait points you are allowed.
Suggestions: Start with a melee/throwing build. Unless you get lucky and find a gun store or armory in a basement (or even if you do find a gun store) You’ll probably have mismatched guns and ammunition. Everything treats a nailball bat to the head the same way and pointy sticks can be upgraded into javelins pretty easily and those can slaughter anything that lives. with 10~11 str even a crowbar gets a serious damage boost.
Most important stats: Strength, perception, intelligence. You’ll want perception at 9/10 so you can see buried traps before you step on them, and on sunny days the glare can reduce your perception by one. Also adds a ranged bonus for throwing and firearms.
Strength is simple, melee damage, HP, carry weight and also a modifier for cutting weapons like swords-- if they get stuck in you can pull them out easier. Intelligence helps with raising all skills and reading some books-- nothing quite like getting to mid-game and having an army of turrets attached to your quadtricycle of doom.
Traits: Quick, fleet footed, night-vision. Personally I take light eater as well, but there are plenty of reasons to take others. The only one I wouldn’t recommend is fast healer, since even severe damage can be mostly negated to moderate by a night’s sleep.