If you haven't had much experience writing programming language, you could consider starting by programming a language that interprets into JavaScript.
For a tutorial on this (and the principles apply to writing any programming language) here's a link: eloquentjavascript.net/11_language.html. I'm building a programming language that interprets into JS currently, and it's definitely doable, though hard, and might be worth starting with.
A compiler that might be worth looking into and that Swift uses is llvm.org
Hope this helps!