Ricing Gnome is both easier and harder than what you see here.
Gnome is very limiting in terms of customization - compared to other DE / WM atleast. That means lesser people actually make cool projects / designs for GNOME, that limits your selection.
But then GNOME is actually quite straight forward when you find something. You can just google GTK4 themes and you should find something on https://www.gnome-look.org/browse?cat=135
Other than that you might start to browse all the extensions. There are many that will alter your layout, give you additional bar, widgets