How long is it expected to take a complete beginner in programming to?
Most colleges that use(d) C as their first language would teach it in a 1 quarter or 1 semester class (e.g. CS10 at UCLA in 1970s-80s). That would give you the syntax and youd be able to do simple programs of a sort. A second quarter (or semester) to do things like sorting linked lists, topological sorts or something else with a graph representation or tree traversal, simple parsing and string processing, implement a quick or heap sort, structs, etc. Today, that class might be Java or C++ or Python. Its hardly a full time thing (after all, students DO have other classes) You probably wouldnt be writing device drivers and interrupt handlers, but after a year (from starting) you probably could do that kind of thing, as long as you got some other training/education on data structures. Mastering it could take a lifetime.