Resources
Game Development
For learning new skills in Unity, my go-to is Brackeys on Youtube. Unfortunately, they are no longer creating new content, but they have a large backlog of content on many Unity features and general game design topics.
For more general ideas on the impact that games can have, as well as game design, I find Extra Credits on Youtube to be very insightful and entertaining.
Programming
My primary programming language is C++. My go-to resources for learning new things about C++ are CppCon on Youtube and, honestly, Google. The recordings of talks from CppCon let me be a fly on the wall and learn about new language features, new paradigms, and pitfalls that other developers run into. The most important things that I have picked up from these talks have been related to writing simpler, less error-prone code. One of the specific lessons I learned was to use ‘const-correctness’ to ensure that variables that I intend to be constants don’t accidentally get changed and cause bugs.
In general, I find that most programming books are very difficult to read and of little practical value. Two that I do recommend are The Ray Tracer Challenge (which you can learn more about here) and Sams Teach Yourself Java. The latter of these does a phenomenal job of laying out the basics at a good pace. The part of this book that really shines is a guided case study at the end. Earlier versions help you apply what you learn to creating an Android app, and later versions help you apply what you learn to creating a Minecraft mod.
Whenever I have questions about a specific programming task, Google has never let me down. Every time I have been unsure on how to complete a task or if a certain syntax was legal, I have always been able to find the answer already posted to StackOverflow or similar forums.