There are wild animals out there to be cautious about, certainly. Wild boars could certainly be scary! However, we humans are bigger than most of the wildlife left, outside of parts of Africa. They’re scared of us. So I’m not usually worried about them. Humans, though, can really scare me!
If carrying a knife makes you feel better, carry one, but using it effectively takes more skill than most of us have. Bear spray or mace is probably more effective for dealing with humans as well as aggressive wildlife. Carry it in a pocket or something where it’s easy to get hold of – not buried under a ton of stuff in your backpack.