what do I have do to improve my programming skills?
throw away all "sample code". Nothing is more deterimental to "improving programming skills" than sample code. When you have "fought your way" through some projects, it will dawn on you.

The process you have followed will never improve your programming skills, but you will be great at copying just like I could copy Greek for years without ever understanding what I copied.

"sample code" can be great when you have developed some code yourself (i.e. understood what it is doing) and you want to see i9f "sample code" can enlighten you on that last little bit you do not quite have right.

A very often seen example: some will copy some LCD code and post here "why does it not work?" which almost always is because they have no idea what it does. one example will be thet with no understanding whatsoever they do not see that some timings in the example and their code (on their processor E.G. 6 clock vs 12 clock) are different. They will be absolutotally lost.

Now for the opposite use of "sample code" When I, long ago, did my first LCD driver, it did not quite work. I looked a someone elses code and saw that (s)he went through initializee twice. When I added that my code worked. Because I had developed my own code, I understood the "reference code" and immediately grasped what was the issue.

Erik