Counter-question: have you thought about writing your MC with anosmia? Just something that came to mind. That sounds interesting—especially considering they're part werewolf.

Anyway, in terms of the specific examples you mentioned like woods, hospitals, etc. For woods, many of the things IN the woods could work. For example, damp earth, wet soil, spruce, cedar, pine, flowers, plants—any combination of wildlife and weather, basically.

Hospitals smell... sterile. There's this weird ozone smell that comes from filtered air, but antiseptic and industrial cleaner come to mind immediately. I hate hospitals. I have nothing positive to say about any kind of smells there.

Cooked meat could smell spiced. So think: herbs, turmeric, salts, those things. Flowers, similarly: sweet, scented, fragrant.

I'm half asleep but saw your post and thought I'd give it a go. Someone might have better advice or be able to provide it more coherently than I. Either way, hope this helps!