Part I discusses why you should consider installing WordPress on your computer.
Part II discusses basic installation procedures.
Part I. Why install WordPress on my computer?
Writers that plan to self-promote their books soon realize the need for having their own website. They’re faced with two choices: do it yourself, or pay someone to build and maintain their site. Many opt to learn on how to make and maintain their own website. It saves them money. They learn how to make quick repairs and updates on their own. They understand how to post and make editorial changes at their own convenience.
To start, they buy a domain name and find a hosting company. The next hurdle is a bit harder, and that’s to decide which CMS (content management system) to build their website on. Many choose WordPress.
Websites abound with WordPress users willing to help others. It’s a vast community. Whether you want to know how to migrate a site from local to server, develop a specific theme, or learn inside tricks and tips, you can find most any video or article on-line on how to do it. Then comes a point that they must dive in and do hands-on work. It’s for the hands-on experience that I’m advocating using your personal computer to learn WordPress.
How? You install an app (software) onto your computer that mimics an on-line server and WordPress. Your computer then becomes a “local” server, as opposed to an on-line “remote” sever.
Fear not. The installation process is easy.
The need for speed
Why should anyone use their computer for learning WordPress on their personal computer?
Developers and webmasters use local servers to test or build a website, and their results are immediate. No lag time that we’ve all experienced using the Internet.
As a user, you’ll want to experiment with different themes and plug-ins to see how they behave, and do some trial and error tweaks with headers, colors, fonts, and plug-ins. You’ll do all this a whole lot faster. Or, you can simply use it as a word processor to lay out your page or post before launching it on-line. (For example, I created this web page on my local WordPress before transferring it onto this site.)
Waiting is not only annoying, but can be a detriment when learning. Studies have proven that immediate positive/negative reinforcement is beneficial in learning an acquired skill. If you follow this link you’ll probably ask what’s the connection between language and software learning? Simple. People learn to communicate with the software’s language, but not vice versa. A Brief Review of Literature on Immediate Feedback Studies in CALL. 
A bit of terminology
There isn’t any need to memorize or understand any of these terms. However, it does help to understand the tools you work with and what’s compatible with your computer’s OS.
LAMP: acronym for Linux Operating System, Apache(Web server), MySQL Database and PHP Language.
MAMP: acronym for MAC Operating System, Apache(Web server), MySQL Database and PHP Language. 
WAMP: acronym for Windows Operating System, Apache(Web server), MySQL Database and PHP Language.
XAMPP: acronym for X (any Operating System), Apache (Web server), MySQL Database, PHP Language and PERL.
Note: XAMPP is popular since it can be installed on any operating system. 
Part II. Install your XAMPP stack the easy way
There are a number of good auto installers out there (Softaculous, XAMPP, for example [3, 4]), but I use Bitnami.  The download/install interface is intuitive and simple. And while you’re installing, keep in mind that you can use an email address. (I didn’t install the Cloud option, so I can’t claim what it does.)
1. Click on the WordPress icon: https://bitnami.com/stack
2. Go to the right side panel under LOCAL INSTALL. OTHER OPTIONS > “All WordPress Installers” is the better option to select. It’ll take you to https://bitnami.com/stack/wordpress/installer.
3. Choose your OS. Choose the “Recommended” (non php) option.
4. Download & install.
5. Once WordPress is installed locally, you need to start your servers.
Start your application.
This is my Linux start-up procedure. Windows and OS X should be similar.
1. Execute the program. This dialog box appears.
2. Open Manage Servers tab.
3. Click on Start All button at bottom. Within a minute, the red LEDs will turn green indicating that the servers are Running. Click on the Welcome tab to go back to the the original screen (Fig. 1).
4. Click on Go to Application (on Fig. 1).
5. Click on Access WordPress.
6. In the URL/address bar, you should have something like: http://localhost:8080/wordpress/
To enter WordPress, the default wp-admin is added after the localhost URL.
Like so: http://localhost:8080/wordpress/wp-admin …then hit Return.
Enter your Username and Password that you created during your setup.
When you see the Dashboard, you’re in!
As you start using your installed version of WordPress, get familiar with the interface. Write a small page or post then add images to see how it functions and looks. Try different plug-ins. Choose different themes to see how they look too, and so on. If you get to the point where you might break your WordPress (highly unlikely), you can simply uninstall, reinstall, and start over.
Remember, it’s all local. No one will see your website until you start posting on a host server.