What should I do when I create a project in qt and get errors from the very beginning? Do I need to customize the IDE?

Question

Qt

Logically, then I created a project, from the very beginning, in theory, everything should be ok there. But for some reason errors pop up, it scares me (I haven’t encountered qt before). I just don't understand, is it supposed to be like this or not? Everything is by default, I didn’t change anything, as I downloaded the IDE, I immediately created the project. Should I set something up or not?

Answer 1

Something went very wrong.
Try to recreate the project, and do not open source files from FM in QtCreator.

Answer 2

There is a manual for QtCreator: https://doc.qt.io/qtcreator/index.html . I recommend to take a look.
PS
... and yes, English still needs to be taught.