Help! There are no package or libraries at net.minecraft.client. that are imported into the mod code.

Greetings!  I can't get help anywhere, I'm not a programmer, however. I want to replace the model of all villagers from the mod with the player model, but I can't compile the java file into a class. The problem is that all the libraries and data integrated into the code are missing from the files of minecraft itself. And I can't understand why this is so, because it's nonsense. The game and mods work fine, but for some reason, when I go to net.minecraft.client.renderer, I don't find the rendered folder and other folders. In the "client" folder, there is only the "main" folder and no more! But mod works and minecraft too. Do you know where I can find the files and specify the path to the?

I only slightly corrected the code, all the imports were already there. Why don't they work, there are no files at these addresses, but the mod works in its original form...