Like most things in programming, 'it depends'! What's your background? If it's in a more interpreted language like Ruby or Python, learning Elixir instead might be a good idea. If you want something that's going to be more approachable, it also might be a better idea. Are you going to do web development, and want to use a more conventions-over-configuration type of framework? Do Elixir with the Phoenix framework.

If you already enjoy Erlang though? Don't get discouraged just because something is built on top of it- keep going! Elixir will be there regardless, and might even be easier to learn when you understand what it's built on.

Elixir is a different syntax and standard library on top of the Erlang VM (BEAM) and OTP, the distributed/HA magic written in Erlang, that Erlang (ecosystem) gets a lot of its praise for.

Ultimately you'll need to know Erlang (language) anyway if you want to use some external libraries that aren't in Elixir natively. IMO, Elixir as a language is not too different from Erlang, other than syntax.

IMO, it depends on your background. If you have a lot of functional programming experience in languages similar to Erlang, I'll say just go ahead with Erlang.

If you come from a more traditional language background, such as C, C++, c#, java, scala, ruby, python, js and others, especially ruby since elixir is very ruby-ish, Elixir is more approachable and I'll suggest that you go with it.