Hey, already lots of good advice here. All depends on the complexity of the apps you want to work on.
Personally, I started with swift, my first and only language (for now) about a year ago. Haven't taken any courses, just started by googling the basics of Swift (arrays, if stuff, for loops etc) fiddling with Xcode playgrounds, watching youtube videos and getting started on a project. Best thing to do is to get started on your project ASAP. Anytime you hit a hurdle, you can find solutions on sites like this, stack overflow etc.
This method's worked for me. Just got my second app in the store last week. Please give it a try and tell me what you think.
App name's SassyFacts. Here's the link:
https://appsto.re/jp/5XqKeb.i
Kinda crazy trivia app with heaps of goofy crap like this thrown in:
Anyway, hope you enjoy it, and good luck with the coding. Seriously, you'll pick up the basics in no time