Install a Text Editor. I use Sublime Text. You will use this to edit your code. You’re going to start needing this at this point in the book.
This is the main tool of your job, and part of the curriculum is getting good with it.
Sometimes, you will use similar tools like XCode for iPhone programming, or Android Studio for Android programming. You end up using a lot of text editors as a programmer - get used to it!
Microsoft Word is not suitable for writing code :)