From your Mac, download and install Xcode from the Mac App Store following this link.
After the installation is complete, open Xcode and select Get started with a Playground:
On the next panel, you can give your Playground a name or you can leave it
MyPlayground and press Next:
Select a location where to save the Playground and press Create:
The Playground will open and your screen should look something like this:
Now that the Playground is on the screen, press ⇧ + cmd + Y to show the Debug Area.
Finally delete the text inside Playground and type:
You should see 'Hello world' in the Debug Area and "Hello world\n" in the right Sidebar:
Congratulations! You've created your first program in Swift!