What you will need:
Autodesk SketchBook (This can be downloaded from autodesk.com. You can download an evaluation version of SketchBook Pro to try before you buy, or you can get SketchBook Express for free. This can be found on the Apple App store, Android store, Windows App store, possibly elsewhere. This is a scaled down version, but completely functional.)
A computer (SketchBook will also work on tablet computers, like the iPad etc.). I have a MacBook Pro. If you are using a PC, some of my shortcuts will be different since you don't have a command or option key.
Wacom drawing tablet. (Mine is several years old; I got it in 2001. It's an Intuos Graphics tablet. It's USB and it still works with my MacBook Pro, so if you can't afford a new one, you could find one used on eBay. If you are going to draw on your computer, it's essential.)