I'm not front end expert, but I have a working knowledge of html & js. I feel like it would still be ok without any JS background, but I could be wrong on that.

That said the language is small enough you can go through the tutorial in a weekend. You'll know pretty quickly if you feel like you're picking it up or feels too foreign.

My gut feel is general programming experience is enough, but don't hold me to that one.

Elm has stopped being updated. I naturally assumed it was quietly abandoned. https://elm-lang.org/news