Time to go Lynel hunting!!
Lynel's have a super cool bow in this game that--for the price of one arrow--will shoot three shots at once! Most Lynels carry this awesome bow on their back and will drop it when killed. Not to mention, they also drop a pretty beefy weapon and sometimes a very nice shield!
The only downside here is the fight itself. Lynels have a crazy amount of health, so fighting them will take some time and will usually break a weapon or two of yours. After I finish a dungeon or am in between tasks in BotW, I'll collect up a bunch of subpar weapons and go sacrifice them into a lynel for their bow, melee weapon and shield. Not to mention, their guts and horns are useful for crafting or selling!
The Lynels in the game can be found in these locations (with the weapons listed by letter):
I've taken this image from this enlightening Reddit post that also includes a little more information in text form in the comments.
If you have trouble defeating them, there are a plethora of online guides for how to handle them. Once you get the timing down to flurry rush their attacks, they get a lot easier!