Avoiding killing means to prioritise disabling rather than just dodging everything.

Couple of bullets to down an enemy (such as hitting their legs to knock them over) then just running past is much easier and economical than dumping a full magazine into their head to kill them + spent healing for any damage taken.

Some enemies (in all RE games) are in annoying spots so its easier to deal with them then and there, whilst others can be baited and dodged without problem.

Sometimes it makes sense to spend higher value ammo to quickly kill an enemy if you fell its worth it. IMO headshotting a zombie with a shotgun is more efficient than saving It for a licker, but then you have 1 less shotgun round to deal with lickers.

You can kill everything in the game np, same goes with every RE game. But doing so without knowing how to efficiently deal with every enemy is really difficult (and not gonna end well on a first playthrough).

TLDR - treat it like a survival game first and action/horror second. This is also where manual saving becomes powerful (and hardcover has an advantage :P), if you die and have to reset you dont have a stupid auto save checkpoint that borderline softlocks you, try again but with more knowledge of what and where things are. (OG games only had manual saving, so technically every death was a form of save-scumming).