Just get a basic bow and wood arrows, make sure you have some stam on you and just kite it around, while shotting at it. It'll take a bit but it's worth it to go after them early for the armor.

Fun fact: If you not beaten any boss's yet, you can still get the fine wood bow by chopping down trees and rolling the logs into the birch trees that are 'too hard to cut' with a flint axe. Repeat and you can break the birch trees to get fine wood. Do this to a few trees and use it to make the fine wood bow. Insta upgrade.