All 3 are excellent open-source content management systems built using PHP & MySQL. While none are a bad choice, I break it down like this.

WordPress is by far the most user friendly. So if you want to do some of the tasks by yourself, look no further. Theme and plugin development is at an all time high. If you need your website to do something, chances are there is a plugin for that purpose. WordPress is also the most search engine friendly right out of the box.
Joomla is also excellent, and user friendly, but it has not grown as much as WordPress. 3 years ago or more I would have leaned towards recommending Joomla, but now WordPress has so many more plugins and themes available plus WordPress has much better SEO capabilities. Another negative of Joomla is limited support for ACL (Access Control List). ACL grants certain privileges for certain users. This eliminates Joomla for enterprise level customers.
Drupal is a top-notch CMS, and the oldest of the 3 having started back in 2001. Drupal is the most powerful and the most technical of the 3, and has the steepest learning curve. If your company employs development staff to make most of the changes and to add functionalty, then this is a good way to go. Be aware there are very few free modules (Drupal uses modules rather than plugins). Also there are very few themes.

To be quite frank, no. It is easy for a novice to add a blog post, images and to edit text in WordPress. But, in order for your WordPress site to be safe, secure and up to date, you need to know how to update WordPress software and plugins. One wrong move can wipe out your website. You need to understand how backups work and how to restore. Also, the premium themes are very difficult and few novices can set them up. WordPress grows more and more robust each and every year, but it also becomes more complicated. Unless you are just looking for a base blog using standard theme, get some help.