[Beginner help] Learning advices

[Toweleeeie]

Hi all,
I'm Alberto, a budding c++ programmer. Right now I grasp the basics of c++;
I'm studying with "Programming
principles and practices with C++" by Stroustroup and I want to start doing
something more practical, contributing
to a real life project like Coreboot. I'm also studying C, as it is the
lingua franca for embedded software programming.
What should I study to start contribute to this particular project? Do you
advise any manual or anything?
Thanks to all of you