How to find out console equivalents of Ubuntu System Settings GUI?

Not sure if this will answer your question because I don't use GNOME, but you can try running

dconf watch /

and see if it lists anything while you change the settings.

There is no general way to do this.

Most Gnome programs do not use command line programs as slaves to set up things.

Sometimes a useful command line program is apropos which searches the headlines of man pages for keywords. Settings concerning the handling of your graphics and input system are often X11 utility programs.

If you want to control behavior of your Gnome desktop you are often stuck with graphical Gnome programs.