The above has been my strategy. Admittedly I've never done coding for pay, however I've been coding my web site, I've written some Android apps, etc.
When I first learned to program, it was BASIC. Later in college Turbo Pascal - which was dead easy to me as I knew BASIC, meaning I knew about the key paradigms of programming. Another decade or so later I had the need to write some small software, and in a few days I got myself going in Python - to this day my language of choice. HTML was added when the need came to design a web page, and the moment it needed more complexity the python module for Apache appeared together with MySQL. I wanted to write an app for my phone, so got myself going on Android and learned the Java that goes with it.
I've taken the same approach with my current business as tour operator. I know my way around my area well, I know many interesting hidden spots, and decided to just start doing tours. The learning how to do it, came as I went. I started by getting some general advice on the Internet, followed by just doing some tours, and see how it went. I learned a lot, really fast. I found out I miss parts of knowledge, and dove into those specific subjects.
Anyway, long story short: my general advice is to learn what you need, as you go.
Your disadvantage is that you don't know any language yet; Python is considered one of the easiest ones to learn these days, and can give you the basics of object oriented and procedural. I can't say "if you know one, you know them all", but that's not too far from the truth. All languages use, at their core, the same paradigms, and those paradigms are the hard part of programming. Understand them, and the language is just a way of expressing it. Also the more languages you know, the easier it gets to learn yet another one.
In this case, based on the comments, maybe you should start learning Swift first. Or try both, spend an afternoon browsing some tutorials in both langauges, and see which you find easiest to grasp. The moment you need the other language it'll come easy. Maybe you'll get a request to add an Android version to an existing iOS app - I'd say just take it, grab the dev kit, learn Java as you go - by then at least you already have a basic understanding of the pitfalls of mobile development, you just have to learn a new language. You may risk pissing off your first employer for Android apps because you're too slow (learning takes time) but the next such job will go a lot easier already.