If your main concern is UI distro doesn’t really matter, the thing you need to think about is desktop environment, most big distros let you choose from a few
TL;Dr I would suggest looking for a distro with kde plasma as it’s quite customisable and looks quite clean out of the box. Personally I prefer gnome out of the two but you definitely hit a wall eventually customising it
Gnome is what Ubuntu and fedora use by default I believe and looks somewhat like Mac (but is fairly distinct from everything else, you kinda have to see for yourself)
KDE Plasma is what the steam deck uses in desktop mode and looks kinda like modern windows.
Cinnamon is what Linux mint uses which also looks like windows 10 and is designed to appeal to windows users
Pop!os recently released their own DE called cosmic, but they were originally using their own customised version of gnome