In reality, version numbers for Minecraft Java Edition began with the Pre-Classic, Classic, and Indev phases before reaching Alpha (which started at version 1.0.0). There was never a legitimate "Alpha 0.0.0" release in the official development timeline. Most "Alpha 0.0.0" files found online are: ARG Projects
However, this alpha version was very rudimentary: alpha minecraft 0.0.0
In short, would be a walking simulator in a 256x256 grid of brown and green cubes. In reality, version numbers for Minecraft Java Edition
If you want to dive into this specific subculture, check out: alpha minecraft 0.0.0