Well if you beat the 4 titans, you should be powerful enough to beat Ganon fairly easily. But, here are some things you may want.
You can get the helmet the Gerudo leader was using, which will allow you to get struck by lightning without taking damage. This means completing all of the Gerudo's sidequests. Along the way, you'll get access to the Jewelry Store which will let you get some items that give good heat/cold resistance.
The Hylian Shield can be found at the Dungeon in Zelda's Castle.
There is a vendor in Tarrey Town that can sell you things you already found. Complete the From the Ground Up and Hylian Homeowner Quests to unlock him.
You can unlock the Sword by finding Korok Village. This is right above central Hyrule on your map. You have to do a little puzzle in the Lost Woods first. You need 13 hearts to be able to wield it.
You'll need to find all the Dragons and Fairies if you want to be able to upgrade your armor to the max.
Those are the main things I could think of at the moment. Again though, you should be good to beat Ganon with what you have now.







