Check out these threads:
https://elixirforum.com/t/learnphoenix-io/1322
And on lp.tv (hasn’t received any comments yet)
https://elixirforum.com/t/learnphoenix-tv/886
I agree that you should learn Elixir first 
and in answer to your last question…
https://elixirforum.com/t/when-learning-what-order-of-books-did-you-start-with/431
