Get a slingshot. It's way better than the bow.
And don't try to fight those boars until you get way stronger. Even with an armor and a sword you would lose a lot of health.
The only way you can do it right now is to stock up on rocks, get a slingshot and a boat.
Lure the boar towards the shore, get into the boat and sail away. Then take your sling and shoot the damn thing.
Be sure to have a rock on the other side of the river, because one inventory full of rocks surely won't be enough to kill it.
And if I remember correctly you'll need a high level of perception which helps you to shoot faster and more accurate.
Trust me on this one. I have some experience.
Ash and I played this game for a long time.
We even had our own village encircled with palisade walls. We also had a mining complex and underground walls.
Even a planted forest with trees of higher quality.
And apples. Because I love apples.