@Discult, i dont am a expert with json files, but i think that you can check older tutorials then the json system dont change. Example:
{
"parent": "builtin/generated",
"textures": {
"layer0": ""
},
"display": {
"thirdperson": {
"rotation": [-90,0,0],
"translation": [0,1,-3],
"scale": [0.55,0.55,0.55]
},
"firstperson" {
"rotation": [0,-135,25],
"translation": [0,4,2],
"scale": [1.7,1.7,1.7]
}
}
}
You can make a model in Blockbench and export it as Json File.