I am 16 years old and want to get a job in the programming field in the future. Since I will be applying for a foreign university, I want to start programming by myself and gain experience, both to increase my chances for quality education and for later employment. Last year I learned Java, but whatever motivation I had mustered fizzled out after finishing the book, and I only did some basic work on a project I came up with by myself, before getting stuck and abandoning it.
This year, I decided to learn C#. My Java knowledge, however small it may be, would help me pick up and remember more information from a beginner book, and since an year of inactivity without much prior experience warrants a reread anyway, I thought I might as well learn a different-yet-similar language, as opposed to just going through my HF Java for a second time.
I picked up Herb Schildt's "C# 3.0 A Beginner's Guide" and finished it. However, I have no idea what to do now. Come up with a random project and work on it (potentially picking up something far beyond my limited ability)? Read up on more advanced topics (even though I don't have any practical experience)? I'm at a loss regarding what to do to actually become a capable programmer, after reading a beginner's book.