Hey Andersonsacanno.
As std10093 has said, C is commonly evolving and many commonly used conventions are changing. There are two big families of standards POSIX and ANSI. I would look up on these.
If you are looking for some older C books that age well / have new editions, the main one that comes to my mind is "The C Programming Language", often called K&R, which I believe is an acronym based on the authors Kernighan and Ritchie.
