"They dont't show you how to develop complex programs that actually do anything useful!"

Without a definition of "useful" there's really not much we can do to get you on the "right" track.

We don't know how you're failing, or what's going wrong. We can't tell what track you're on.

Somehow, you have a notion in your head that you're not communicating.

Software -- programming -- is all about getting a notion out of your head into some language (Python, Java, English, whatever).

One important step in programming (and asking questions) is to define your terms. What do you mean by "do anything useful"? Be very clear, very complete and very precise.