I think the bigger issue between Elm and Clojurescript is that while Clojurescript is a language, Elm really is a total toolkit for web application development. Elm has its own virtual DOM, various types for interacting with the browser, and is very possesive of the DOM making pulling in non-Elm code challenging.
Meanwhile writing a web app with Clojurescript will require making more choices around libraries you want to pull in, although you can always just go with re-frame which is awesome.
As far as more theoretical learning, I'd go with Clojurescript. Clojurescript is a real lisp with all the fun stuff you can do there. Elm is an intentionally gimped ML variant made so to make it more palatable to the Javascript developer community. If your goal is to learn about typed FP while running in the browser, you'd be better off with ReasonML.
If OP is a beginner, I think Elm's integrated approach (less fighting with build tools), pretty good docs, and larger ecosystem will be easier to learn than the more powerful, less united, and less documented ReasonML.
I've been doing a bit more elm (some at work) and I've tried to get into Reason from time. I always aborted on the first day. Last time I tried to learn ReactReason in december, I think their VSCode tooling wasn't working at all.
Meanwhile writing a web app with Clojurescript will require making more choices around libraries you want to pull in, although you can always just go with re-frame which is awesome.
As far as more theoretical learning, I'd go with Clojurescript. Clojurescript is a real lisp with all the fun stuff you can do there. Elm is an intentionally gimped ML variant made so to make it more palatable to the Javascript developer community. If your goal is to learn about typed FP while running in the browser, you'd be better off with ReasonML.