Should I learn it?

[WingedPanther]

They can be learned in either order. I recommend learning C++ first.

[G_Morgan]

I think the real issue is learning procedural programming before OOP. C is procedural, C++ is a mixture of both. To learn C++ you must learn how to use procedures at some point, even class members are just procedures with an implicit 'this' pointer.

For this reason many suggest learning C before C++. You can use C++ as a 'better' C though (string handling is much nicer in C++ IMHO) and not bother with C altogether. I would learn both though just because 99% of C is on the C++ standard.