Can you write a website in other languages, like c# or python?

Yeah, anything that outputs HTML and CSS can do so. There's a module for Apache to write webpages in Python (libapache-mod-python) and I'm p sure someone somewhere made a module to do it in Rust already except they're infighting over whether tag parsing in it should be marked unsafe.

For that matter you do can write web pages in your shell eg.: bash, that's what CGI is all about.