Check out this Link (Ha!) To help you on your mission. It’s a list of all items in BoTW. I believe there is a page on there for weapons as well.
Now for your conversion; the vast majority of the items/loot available are ingredients and food. I would maybe think of doing something “color coded” for different effects. All red mushrooms grant fire resistance, blue mushrooms = cold resistance, etc. Obviously flavor to your own preference. If you want cooking/combining ingredients, maybe you choose up to four ingredients to get a combined effect over a number of rounds/phases. If the players start combining random ingredients you could maybe build out a few roll tables and make “recipes” based on roll results. In amy event, I seriously pare down the number of “ingredients” available to players either through limiting player inventory or just making the collection scarce. I’m more a fan of limited inventory, especially when dealing with playing Legend of Zelda.
For weapons and armor, I think I would go along with having “quality” levels of each weapon. To simulate the weapons getting damaged and breaking you assign each level a number of failed attacks based on their quality level. “Pristine swords break after four rolled 1’s on attacks” or something to that nature.
I’ve kinda gotten long winded here, but I’ve always thought Zelda would make a fun Rpg. I’ve got a few links saved somewhere for some different home brewed worlds and systems for Zelda, if you are interested I can track them down and post them here. If I had more free time on my hands this would be a project I would love to pursue.
Thanks,
Chris