I need help with custom code and armor

I need help with armor i made custom armor and then it said it wasnt an armor texture and when I made an armor texture through MCreator it accepted it but mine it didn't even though it was the exact same layout.

I also need help with a custom code problem. I am trying to make a code for boots when you jump it makes a sound effect. Problem is I don't know anything about coding. Here is a screen shot