

I recommend starting with basic operations, like:
- putting installed files in the right directory structure.
- integrity checking.
- archiving and compressing.
Decide whether your package manager is source-based, or if you’re going to make some kind of binary distribution mechanism. Either way, you’re going to need a process for configuring, compiling and installing packages from source.
I do recommend looking at how Pacman, & apt approach all this. There are also likely books on this topic.
Also recommend playing around with buildroot; not because it is a comprehensive package manager, but because it’s inner workings are very transparent.


Start with a portable hard drive which only has one job “store a copy of your critical data”.
It’s a paranoid set of rules, but if this data is critical, this is a good idea. Even better is to have an additional copy of that data in cloud storage.
As far as operating system, you absolutely can use a Linux machine, but learning a new system risks you accidentally deleting data so be careful. Linux has ways of reading windows-formatted hard drives, so as much as I prefer Linux, I would say don’t try new things on the machine which hold critical data.