If it's for a hobby project it can be fun to work with Common Lisp and see all the good things such an old language still has to offer and where it's still superior to more modern languages. You also don't need to deal with the JVM and will have nice stacktraces (Clojure stacktraces are a mix of Java land and Clojure land). However the ecosystem is very thin so you might have to implement more stuff yourself or being blocked on something (no asynchronous programming for example if you need a very high performance web application). It's not rare to search for a library and find that the last edit was 7 years ago. Maybe it works, maybe it does not, but it surely is not maintained.
The interactivity in Common Lisp is a bit better (navigate the stacktrace, debugger, object inspector etc) but the Clojure REPL is also very good and allow to change the code of your application live without recompiling the whole project. Clojure is a functional programming language, whereas CL is multi-paradigms so it's easier to deal with state in Clojure. The ecosystem of Clojure is much richer and you can always fallback on the endless Java ecosystem if something is missing.
I'll invite to explore the CL ecosystem starting with https://github.com/CodyReichert/awesome-cl/ (it might be larger than one thinks)
In terms of asynchronous programming, not built-in to implementations (like, no green threads), we have
- https://github.com/orthecreedence/wookie - an asynchronous HTTP server
- https://github.com/fukamachi/woo - fast non-blocking HTTP server on top of libev.
- an actor-based task manager for Hunchentoot: https://github.com/mdbergmann/cl-tbnl-gserver-tmgr
see also https://github.com/CodyReichert/awesome-cl/#parallelism-and-... for promise libraries, async libraries, the actor library, an STM library, lparallel (run tasks in parallel, easy and often useful), bindings to other async tools.
Those libraries are active.