Linux User is Getting a MBA Tomorrow: What Will I Be Missing?

I'm using Ubuntu on my loyal Thinkpad x220 and Arch on my powerful workstation, yet, tomorrow I will get a MBA (M4). What should I prepare for when taking my first steps in the fruitful world? What will I be missing?

I do have some questions:

1. Is there anything that should be done early on, because it will make my life easier later, e.g. I read something about a specific tool that allows me more easily to uninstall and get completely rid of software, or maybe some specific backup tool?
2. Does software update itself, or is there something like a package manager that takes care of it (like apt or pacman under Linux), or will I have to keep an eye on everything and hunt for updates on a regular basis (like in Windows)?
3. Most of the code I write is written in C. Do I need a specific compiler or plugins or anything like that, or will I find gcc working out of the box? (I need openMP and MPI as well).
4. I heard XCode should work quite nicely and I will happily give it a try (otherwise I am using VSCode).
5. What steps can I take to protect my privacy and limit communication between my device and the Apple headquarters?
6. How is the window management? I do like a good tiling with workspaces.
7. Is there something like Borg for backups, something that takes a snapshot every day, integrates the incremental changes, and compresses everything?
8. Is the integrated e-mail client worth it or should I ditch it right away for Thunderbird or outlook?