You should check out this site if you are interested in learning more about web design.

https://www.w3schools.com/

I used it for a lot of CSS stuff that I was working on a while ago and it was awesome. Unfortunately for you, I haven't coded in C++ for close to 25 years so I probably won't be able to help you much with that! I have been looking at picking up a coding class myself. Not sure what yet.