Does Ubuntu have a "regular" desktop or are is it still stuck in that "Unity?" desktop? I went to Linuxmint after that. Is it either - or? If you can choose a "regular" desktop is easy to get or do you have to fiddle around to get it?

Ubuntu uses a customized gnome desktop by default. They stopped using Unity as default desktop ~5 years ago. Their gnome desktop setup includes a couple extensions, including dock to dash and appindicators.

If you want a different desktop from the get go, you install a different flavor in the first place. They have kubuntu for plasma, xubuntu for xfce, lubuntu for lxqt, and quite a few more, including one for unity that was recently brought back. This info isn't hard to find....

Additionally they all use the same repo, so you can install ubuntu server then install whatever desktop or window manager you want, including ones not offered in official flavours, or start with any flavor and install another desktop as well.

Look into Gnome-Minimal Desktop. Also into installing Gnome-Core.

You could also look into Debian and use the Net installer iso image which will allow you to choose the desk environment)s) that you want on your system or you can just opt for the base system. If you take a pick that route it will give you the broadest choice of window-managers and Desktop-environments. Youl also be able to hand build your system with every thing from the email client that you desire right on down to yoiur personal favorite cli based text editor.