Problem with creating new C++ Class

I have installed visual studio 2019 including c++ toolchain and when I try to make new c++ class from the edit dropdown menu while inside a project I get an error and I dont know what to do after I close the log. (edit: I get the error after I give the class name and click CREATE and after a little loading)

note the project is called Cplus and the c++ class I tried to create is named ReadWriteFunction

also note that I never done c++ classed before and what I do is follow this video : UNREAL 4.26 READ WRITE TO FILE from BLUEPRINT How To Create C++ Class Calls/Functions 2021-Training - YouTube where at 6:50 things looks different from my result which is simple error and nothing new appears

Now when I open the project I get this (picture 1) before it opens and when I select YES I get the other thing (picture 2). How do I set it manualy ?

This is all normal. When you add a new class, you’ll have to recompile the project.

Thank you so much!