Suggestions:

1. More requirements helps. What kinds of production-grade software?

2. For most purposes, you won't see the real benefits, compared to contemporary alternatives, until you have some experience with the Lisp. Enough experience that you realize that, although you can write in a Python or Ruby style in a Lisp, to some degree, there's other various idiomatic programming that's a bigger win sometimes.

3. Once you have some reasonable level of experience, (I'll assert) there's a good chance you become more productive than you would be with a comparable amount of experience in most non-Lisps, in general. But there are some big exceptions to that, such as if you need to do something that can be solved with an off-the-shelf library that's already easily available in Python (e.g., a wealth of ML stuff), for example, and you'd have to write that or an interface for it in your Lisp. Writing it yourself often means you understand it better, and can make it do exactly what you need (including possibly big advantages), but it's an investment.

4. Pick a language and a particular implementation. and make an active user community of that implementation one of the requirements. One of the advantages of Lisps is that they tend to have great communities, perhaps because there's usually little money in it, so you get high-powered people who are there for the merits of it, with a lot less noise. But you do want to find one that's being actively maintained/developed, and that has an active user community.

5. Beware that most development hiring right now seems very driven by fashion, "culture fit", and keywords -- a lot less hiring for "smart, and background they can draw upon to pick up whatever new/other thing is needed". So if you get stereotyped as a "Lisp person", or you don't have one of this year's hot stack keywords on your resume, your next job search might be surprisingly difficult. To a large extent, if you used unfashionable keywords, it doesn't matter if you single-handedly had major accomplishments that would normally be extremely impressive to employers. There are very few Lisp jobs, and there have been very few for a long time. There's a niche for CL, but also a wealth of CL gurus already existing that you have to compete with. There's almost no paying work in Scheme, unless you already have the non-Scheme-specific job and can then pick your tools (i.e, professor, startup, or unusual corporate latitude).[1] If you want to move to a Lisp, but might have to job-hunt in a couple years, Clojure might be the best bet, in that regard, at the moment.

[1] For years, AFAIK, I might've been the world's only consultant specializing in Scheme. But I'm shutting down my business, because there still seem to be only a handful of funded projects using it, outside academia (for university consulting, you need a rare PI and situation, for this to be good) and government (federal subcontractor overhead is a huge burden). Most of the few commercial projects using Scheme are one-person, and don't need anyone else.

(Background: I've done serious production work in Scheme for several years, on some important Web server and cloud technical data science stuff. I also played a very small part in a major project in Common Lisp, using SBCL, and bumped into a bit of CL at another job. And lots of production and research work in C, C++, Java, Python, Perl, etc. separate from that.)