Hello, unfy!
I’m C programmer too and I learning SDL2 now. I learn it myself without any tutorials, using just SDL-wiki (http://wiki.libsdl.org) and this forum. And sometime looking to SDL2 source code (it’s written in C). I making simple test programs for different aspects of SDL2 and learn how it works.
I think we need more SDL tutorials in C - it is good idea. But for now we can learn using this resources, which we have. We can learn SDL2 + C programming together if you interested 