Oh. I mean, why do you think you need to get familiar with Debian first then Devuan? Why not just use it directly, if your target is Devuan?

Judging from your question, I think you have not even touched them at all (if you have attempted to try them, your question will be different and more specific, like what doesn't work etc).

Debian/Devuan and both are convenient and easy to install(https://www.devuan.org/os/documentation/install-guides/chimaera/install-devuan) or use, with their desktop ISO. You don't even need to know Unix commands to finish the install, and I think the only things that might get you lost after the installation are, adding your user to sudoers (with things like visudo with root), and editing the repositories list (https://www.devuan.org/os/packages).

Anyway, the only way to get familiar with anything is to use them. Without trying them you never know what you don't know. There is almost no cost trying the distros. You can always experience them first like in a VM, or with a live USB or a installation on external drives to test the hardware compatibility.



Btw, how should I ask that in Japanese? (about my previous reply)