Change the "explode" sound and the "item.shield.break"

Hello ! I would like to change the explosion sound (creeper / tnt) and the sound when an item break, but i dont know how to name the folder properly. The only thing i was able to make is change the ignit sound by creating the following folders : 

sounds > random > fuse.ogg

But i dont know what's the name of the others folders. Can i get some help please ? Thanks !