Re: Learn to code
A programming language is just a tool you use to create something. So learning to program is not really language specific but more a conceptual thing. Actually it's mostly about solving problems or how would I make this do what I, or the one you build something for, want.
How you solve something does have a relation to the tool you use, because different tools use different ways to get where you need to be.
Usually you'd go through a study in computer science or programming, but there are a lot of people (specially age 50+) that changed carreers later to become a programmer with a mathematics or physics background. There are plenty of courses to learn specific programming languages, but as a programmer, writing code is mostly the smallest part of it.
I hope this still makes sense
To get back to your question, swift playground does get you into the basics. So I think it would be an easy way to see if you actually like programming. Although, for as far as I've sene it, it doesn't really learn you the whole part that comes before actually starting to build something.