Here’s the thing: if you’re a user, why do you care what language the software is written in, as long as it suits your purpose? And if you’re a developer, you just need to build something nice to get a feel for the language. No need to “prove” anything. We don’t walk around with chips on our shoulders here and IMO that makes things much nicer. 
So, that said… even if you don’t feel that your skills are up to par, go for it! We’re here and on Slack to help get you unstuck from the tricky parts. One nice thing about Elm is that even if you begin poorly it’s easy to refactor later, since the compiler will help catch mistakes. So the best way to learn here is to do!