To make a minecraft texture pack, it requires a few steps. This tutorial is going to go over making a simpler one just to change existing textures, not adding new ones. first you are going to want to open a new folder and name it whatever you want. Then make a new text document called pack.mcmeta and put this in it.
you can change the your description to whatever you want.
Then open paint or whatever image editor you are using, and make a 64x64 pixel icon called pack.png. This is the icon when you are applying the pack. Time to make the actual pack now. In that same folder make a folder called assets and in assets make one called minecraft, and in minecraft make one called textures and in textures one called painting. We are going to be editing the paint textures. go to C:\Users\*****\Appdata\Roaming\.minecraft\versions open up the 1.16.5 jar with 7 zip or turn it into a zip. Inside this folder we will be going to assets\minecraft\textures\paintings. Copy the paintings you want to change into the painting folder of the pack we are making, and edit them how you like. Now drag the folder to your resourcepacks, and enjoy your new paintings!


{
"pack": {
"pack_format": 6,
"description": "you're description"
}
}