Lets learn c++

Some years ago I looked into c++ but I lost my interest cause I didn't found an easy example how u make a UI and so I didn't found a use of this language for me.
Now it's different.
I wrote a program in Java and it was laggy. I don't know why. After some tests, I found out it has something to do with the libraries I'm using and my response will be to switch the language also I missed in Java things like a reference to a variable or a pointer.
So I want to look into c++ again and this time to go further.
I will also share my progress with u to show how easy it is to learn a programming language.
And I will start learning with an APP I found called "SoloLearn". I really can recommend it. It's easy to use and helps u get right in.
Sololearn
I just used it for fun but now I know to use it.
So let's see how far I get in some weeks. If u can recommend me something especially about GUI to look in then feel free to share this source in the comment section. Thanks