Question about intelliJ java setting

Are you trying to run a project that has already been created with gradle? If this is the case, select Import Project > Select Project > Import Project from External Model > Gradle to open it instead of Open on the Intelligence initial screen.

From the top menu, in the File > Settings > Search pane, under File and Code Templates > Files tab > Class, you will find the format for creating class files. It is possible if you modify it like the picture below. I don't know the other way.