For instance "I'm new to Lisp, I want to try one..." is a person without a lot of background and information to make that choice. And they probably realize it and it makes them nervous about making that choice.
Warning about the issues that come with ANSI CL's frozen spec (threads/sockets/unicode/extensible sequences/gray streams/etc... as extensions with a varying amount of support with compatibility layers often available to write portable-ish code, "bolted-on" CLOS never fully integrated) and its various rust spots, not just the good points.
Mention that CL has provisions for gradual typing (with limits) which are exploited by SBCL.
Scheme, obviously, along with the same warning as CL about pain of writing portable code that interacts with the OS (does it have compatibility layers like CL?) amplified by the R6RS vs unfinished R7RS-large mess.
A few words about the build system/third-party packaging situation and alternative implementations.
https://github.com/modus-lisp/modus
Since you can't use an OS by itself, I've rounded out the Common Lisp environment with portable ssh client and server, web browser, and a bitcoin node. Framebuffer with VNC in the pipe
God help me if I fell down a hole like that.
I must say, however, that e.g. code like (compile-compound) is something only an AI can love!
A road to Lisp: Why Lisp
Lisps have many fantastic ideas, but are really hard to read. Lisp code is what we had before perl guys went "hold my beer".
I know its just syntax, and it usually does not matter, untill it does. I did some clojure a long time ago, and before that some CL, and god, i cant understand my own old code. Contrast that to some language that has syntax i can read it still, years later. Go being the prime example of write once, read a decade later.
Once you get hang of it, it easy. Following is video of my son who learnt Scheme as first programming language.