just go deeper on both,

I would say move on to C++, C++ is actually easier than C in my opinion

If you care about her/him, you''''ll listen
If you love her/him, you''''ll heal his/her wounds
If you like her/him, you''''ll do all of the above, and help her/him in need

A person who cares is a person who never speaks

First thing you have to know is that C++ is a superset of C, which means that C++ extends C by adding wrappers (classes) and related keywords (access specifiers, new, delete, static_cast, reinterpret_cast, friend, template, ...)
Off course there are changes added to C, such as
type casting rules and the boolean type to name a few.
You must be aware of the fact that you can translate C++ code into C equivalent, which in turn implies that C is object oriented.
Go on with C++ and deepen your knwoledge, and be aware of major differences between C and C++, which are all related to how the C++ compiler interpret things. Beer in mid that a C++ compiler compiles pure code (no C++ specific keywords) and the opposite is false.

To name good books:
*** C++ How to Program by Deitel.
*** The C++ Programming Language.
*** And the MSDN C++ Language Reference.

Enjoy learning and coding.