Yeah, phx_gen_auth hasn't landed in main phoenix yet. As another poster mentioned, you should try https://github.com/aaronrenner/phx_gen_auth if you're going to use a generator. You might however get more mileage out of Programming Phoenix[1] where you'd learn what all of the files are for and how to build auth yourself. Plug and Ecto make it quite easy to do password auth. Guardian was popular in the past, but isn't widely used these days. You could use joken, or just roll it yourself.

Generally the docs for Elixir libraries are very good, but you have indeed found some poorly documented things. I might suggest scraping together something simple and then trying out parts of the ecosystem that offer something new, like channels, live_view, broadway, or something else that takes advantage of OTP. Otherwise you're only going to see the gaps compared to Django and none of the benefits.

[1] https://pragprog.com/titles/phoenix14/programming-phoenix-1-...