Hey, I know a decent ammount of C++. Here are some of the concepts that I'm familliar with:
-Declaring and manipulating variables
-Declaring and manipulating functions with and without parameters
-Data types (like char, int, bool, float, etc.)
-If statements
-Switch or case statements
-For Loops
-While loops
-Do...While loops
-Pointers (working with memory adresses, still learning this concept)
-Classes and OOP (Object Oriented Programming)
-Header files (these are pretty straightforward)
-Having multiple files in one project
-File I/O (Still learning how to manipulate files)
-Recursion (using a function multiple times)
If you would like some help learning the above concepts, hit me up on steam, zwyx12341 (dont forget the extra 1 (one) at the end!). In my spare time I will gladly help you to learn to code in C++, should you want it.
As far as game programming goes, I made a tic tac toe game in C++. It's still a work in progress, but I can PM you the github link if your interested. I'm currently working on a chess game in Python, a different programming language. I know Python better than C++, but im at about an intermediate level in both languages. I also have a collection of text based games in Python. Should you want to look at those, I can upload them to github.
As far as GUI (Graphics User Interface, google if you don't know what it is) programming goes, that is a lot harder. I suggest you work your way up by making console applications (things that run in command prompt or a Linux terminal) and go from there. You can make some pretty intense programs that are completely text based. I made a program that was simillar to a journal, except it asked me pre-defined questions and I answered on a scale of 1 to 10. It then logged my answers to a text file. If you notice, I dont have much experience writing GUI's in python or C++, thats my next goal after file I/O. So yeah, GUI's are quite hard in my experience. I've attempted GUI's before, and never got very far with them.
All in all, I wish you the best of luck in your programming adventure. Should you ever want my help with coding, just shout. I have a passion for art and programming, so its not a burden on me. Just ask.