Object-Oriented Programming or OOP is used by almost all of popular coding languages such as Java, Python, PHP, etc. Learning C prior to code in C++ can help you to better understand C++. Also, prior knowledge or experience with OOP and its concepts would be a great if you like to learn C++. Both C and C++ are mainly used by software engineers or those who work with computer hardware. Most of computer operating systems like Microsoft Windows, Linux, Mac, etc are written with C and C++. Both C and C++ are taught in all software engineering, electronic engineering, telecommunication and computer science schools.
It is advisable to consult with an IT career counselor to understand what career options best fits your skills. For instance, if you want to be a software engineer, learning HTML and CSS might not fit the bill. Here is an excellent article for learning more on coding and technology career roadmap. Once you know what career path you wish to pursue, you can make a plan on what, when, and how to learn. There are lots of online resources for learning coding and technology in general. For teenagers and high school students, High School Technology Services offers variety of hands-on training. For adults and professionals, Coding Bootcamps and DC Web Makers Companies offer basic to advance project-based programming and technology classes.