If you plan on remaining a member of Wealthy Affiliate, then simply use Wordpress Express, which is design for easy installation with WA hosting.

Wordpress.org is for individuals that have their own hosting and want to use Wordpress on their sites. You have your own domain and everything is designed for manual installation and maintenance because you have complete control of your own self-hosted blogs. This usually means that you are familiar with programming and have a working knowledge of coding languages such as HTML, PHP, and CSS, as well as a mastery of Wordpress and installing plugins.

Wordpress.com is for people who do not have their own hosting, but simply want to start blogging. Wordpress hosts your site, and your domain name will have the .wordpress.com extension. The problem with this method is that limited to what themes you can use, what plugins you can install, and you cannot monetize your site, meaning you cannot place affiliate links or make money with it.

The honest truth is that Wordpress Express here at WA is the best. I've checked out WP.com and it is limited in what you can do; i.e. can't add widgets. Got rid of it. WP.org is probably more for those who have some experience with coding, etc as I understand it is more for developers. That's what I've found in my travels. The WA WP has been the best from my experience for being user-friendly and easy to learn.