Initially, I was going to use WHMCS because of the tight integration with cPanel as it was built to accommodate selling web hosting but then I felt it was a bit overkill for what I needed.
it is really useful to get a grasp of Views Contextual Filters for Drupal 7.
Installing Drupal 7 locally (using XAMPP)
Drupal is a huge software project by any measure, with thousands of developers writing code for it and deploying websites and applications on it.
Command line shell and scripting interface for Drupal. This video explains what it can do.
The video says it all. https://www.drupal.org/drupal-7.0
Recently, i've had a few requests from design companies asking how they can make Drupal Admin UI feel a little like Wordpress because a lot of their clients have become accustom to using Wordpress admin UI and is comfortable with administering their site with a separation of the front and backend.