Is LISP still useful in today’s world? Which version is most used?

“I try to teach myself a new programming language in regular intervals of time. Recently, I’ve read how Lisp and its dialects are at the complete opposite end of the spectrum from languages like C/C++, which made me curious enough to know more about it. However, two things are unclear to me, and I’m looking for guidance on them :

  1. Is LISP still practiced/used in todays world, or is it a legacy language like FORTRAN/COBOL ? I mean, apart from maintaining existing code, is it used on new projects at all ?
  2. What is the most widely used dialect ? I came across Scheme and Common Lisp as the 2 most prevalent dialects, and wanted your opinion as to which is the most favored/useful one to learn – and would be immensely gratified if you can suggest any resources for a rank beginner to start from.

While eager to learn a language which is fundamentally different from the procedural languages I’m used to, I don’t want to invest undue effort in something if its totally obsolete – I’d still learn it if it was professionally “dead”, but only with an academic perspective…”