Since you already aware of C programming so you would have to understand the additional Syntax for C++ . C++ is useful if you want to move towards object oriented programming language. One can always write a C Coding style in C++ which will not serve the purpose of C++. There are many videos online available for free but most of the time when reading online we skip some basic sections if the tutor has missed, If you are learning it first time i would suggest buy a book on C++ by Herbert Shield or Thinking in C++ , these are books which detail every concept. T have exercises one every section solving them builds your knowledge on the basics.
P.S. What we have just discussed is not exhaustive. There are so many more resources for beginners to start with, from online courses to books.