There is no difference between installing software on a VM and on "bare metal". The OS takes care of the hardware stuff.
I installed it according to their manual on their website (https://radicale.org/v3.html) which is imo pretty easy. The TLDR is that you first install python3 and its package manager pipx, then you install radicale using pipx and finally you run it as a systemd service. You can just copy their service template. The issue comes when you need to run multiple web services though. Radicale wants to be on the website root (website.com/ instead of website.com/some/path/blablabla/ ) which is not as trivial to set up as the previous steps. They have a template for nginx and apache but you need to kinda know the very basics of one of these to set it up.
Also on debian there is a package so you could technically just apt install radicale and then systemctl enable radicale if you want to avoid creating a service and installing python.
Obviously you need to create a basic config either way according to their manual. At least for password authentification.