I think that all the flavours of Ubuntu use the same installer. At least they did when I tried out different flavours some years ago. So, the screens you saw when installing Ubuntu you will see again when installing Xubuntu. The colour scheme will be different. The method and information required will be the same.

I installed Zoom Client for Linux from the Zoom web site. It was an old version without some of the better security features of the later versions. Since then I have installed the snap app version of Zoom Client. It is at version 5.1.4 having had several updates since I installed it in March.

https://snapcraft.io/docs/installing-snap-on-xubuntu

You can install Zoom-client snap from here.

https://snapcraft.io/zoom-client

Regards