Also in pure C you have to declare all the variables you are going to use in a function, at the start of the function.
True, that's one good reason to start with C++ (in addition to the handy // comments, etc.) - C's requirement that all variables be declared at the start of the function is not only tedious but usually results in far messier code than what C++ allows, so I guess it's best to start with C++ and learn good habits from the beginning. Like you say, there's no need to learn the OOP features until you're ready, because unlike Java/C#, C++ does not force you to use OOP everywhere.