How would you recomend someone start learning to create custom bots?

One thing not mentioned in this thread - when you develop with programming language you need a good code editor.
Most popular is Sublime, but you need to pay for it. Mirror of it will be Brackets - its free and full of nice plugins + it is developed by Adobe.
Some use notepad or notepad++ but likes of Sublime can be huge time-savers + they usually come with dark background. The last point is quite important as you can code longer without tiring your eyes using graphite color background.