You can watch the Fundamentals of Materials and Shading course to get a much better understanding of the basics, linking up:
https://cgcookie.com/courses/fundamentals-of-blender-materials-and-shading
As Omar said, the Fundamentals course is great to get up to speed on those. But really, like everything in blender, it just takes some time. When I started the courses I felt like there was a lot I wasn't understanding on the technical end (there still is, im far from experienced). But the more and more courses you do, the more repetition of a lot key elements like shading and geo nodes become easier to understand. Keep it up, you learn more every day!
No worries Nedy_Pictures - it's good that you didn't let the materials stop you. Eventually it will click and you'll be like Neo seeing the matrix