Is there any Queue data structure implementation that "comes" with C or will I have to develop my own (this is for a school project, thus I must use something that either exists in the standard gcc installation or have to implement one by myself!)
What about other general data structures like Linked Lists, Stacks, etc?
You must implement your own. C has very little in terms of data structures and forces you to resort to arguable tricks to implement abstract data types: see an article titled “Incomplete types as abstractions” if you can find it, or see how the principles are applied in, say, PolarSSL's bignum.h file. C++ on the other hand is supposed to allow you to do pretty much everything you can do in C and give you ways to implement abstract data structures.