distros themselves don't look like anything, it's the desktop environment / window manager that you see, this is a wm called hyprland and you use mostly .conf files to change the look, but some things like the bar at the top (waybar) use css
this is a distro called arch and its really complicated tbh, but you can totally get a "just works" distro like pop_os or nobara and it'll be really easy :)
The goal of using a window manager is basically making your own custom desktop. The majority of apps are configured through text files. If you want to try Linux, you can pick a beginner friendly distro like Fedora which will give you a desktop environment. These are desktops with the batteries included and are fully customised through GUI settings menus.
Fedora KDE is a great option if you want to try making a very custom looking system without having to worry about installing a ton of different tools and editing config files.