Mixing Minecraft Texture Packs?

I wanted to create a texture pack by, for example, mixing the items from the Texture Packs X and the blocks from the Texture Pack Y, but unfortunately you can't paste in a ZIP folder or move anything into the ZIP folder.
That means if I now copy the items folder from Texture Pack X and want to paste it into my own TexturePack, it doesn't work. If I unzip the ZIP folder, I can create everything, but if I make a ZIP folder again from this folder, Minecraft no longer recognizes the Texture Pack and I can't use it.
And that is not because I did something wrong, but because in this ZIP folder there's again the folder in which first the folder assets → minecraft → textures and then the folders like gui, blocks, items… Is inside.

Therefore it is not recognized.
Does anyone know how to do it any other way?

Do not compress the folder, but the files in the folder, then it should actually work. Also assets, pack pack.mcmeta etc.

Many Thanks. Do you know where in the texture pack you can find what the background looks like? Because I changed the earth blocks in the Texture Pack, but in the Minecraft menu there are still the normal ugly earth blocks. Do you know where to get the png. File with the cover image?

Main menu or options? When it comes to the options, you have to change the "options_background.png" in the folder assets> minecraft> textures> gui accordingly. YouTube, which is easier to understand then. I don't know whether to use options and server selection etc. For the background, because I always ignore backgrounds, it takes me too long to open Minecraft and because I usually leave things as they are when I create a texture pack. But I can recommend that you download one or the other known texturepack such as From BDCraft and you look at the folders, names, etc., that can already clarify many questions.