It does not require a lot of time and money to learn WordPress. You just need to  know how to Google and the ability to follow the instructions on the selected link.
There are many tutorials like  Team Treehouse, WPBeginner etc. You also have the resources at the official site which has free content.
While learning, you would definitely need to install WordPress in your system to practice simultaneously. You can search for WordPress Installation Tutorials. There are quite a lot which are well framed.
Once you learn the basics of WordPress, you can start brainstorming on the best plug-ins  and themes and learn how to customize them for various types of websites.