As you learned earlier, launch Xcode and click on Get started with a playground:

The Playground template screen will appear. Make sure that you select iOS and then choose Blank and hit Next. You will be asked to give your project a name and a location to save the file; name your new Playground iOS11-Programming-for-Beginners-Ch3. You can save the file anywhere you like. Now, with the project saved, we can explore Playgrounds a bit.