Help - 2 different websites which one is legit?

There is this website: A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums

and this one : Unreal Engine 5.2 Documentation | Unreal Engine 5.2 Documentation

Which one is the official website? Because I followed that water shader tutorial on that first link and it produces some black bouncy effect. Just felt like I was being trolled.

Both are. The doc. subdomain is the official documentation while the wiki. subdomain is the community wiki which is maintained by the community itself. If you find some issues with the wiki page you can contact the author of it and send him your issues, or even better just fix the issues and update/contribute to the wiki.