Once again - I asked what you find hard in the chapter you're on - not what chapter you're on.
Cause I don't think you won't be able to understand:
"Why make games?" or "OpenGL History"
I mean if you want some help you should say where you got a problem - something concrete - like saying "I don't understand the graphics pipeline" or "I don't understand Matrix multiplication" etc.
This might be a pretty wild guess - but maybe you're not ready for OpenGL if you can't even understand the first chapter. Maybe you need to start with something easier - like a ready engine or something like that. For example you say that you finished learning the basics of C++ but I don't think basics will be enough for working with OpenGL...