Thanks for all your help above - I'll definitely consider keeping the original Mac OS and running Linux Mint. Is this a bootcamp thing or something to do with UEFI? EG: Would it mostly be booting into Mint and only occasionally going into Mac OS if I hit the magic UEFI button and interrupted?
It's multiple bootable partitions. It's not inherently UEFI dependant, but in the case of your Mac it would be loaded through EFI, yes.
Bootcamp sets up a Legacy BIOS style computability layer in the EFI, with a Master Boot Record hybrid section on the partition map of the disk it installs to; None of that is necessary for Linux - strictly speaking not necessary for Windows either, but I'd argue less so for Linux.
When you boot a Mac, you can hold down the alt key to select which media to boot from. Within macOS you can also set the default boot source inside System Preferences.
So yeah, if you just install Linux to a different partition on the same disk, or even a different disk, you can set it to boot automatically, but if you hold the alt key when turning on the computer you can pick an operating system.
You can also get boot-pickers so that you can boot into a menu for picking an OS by default - GRUB usually does this for different Linux installations on the same computer, and there's also rEFInd which is quite liked by a lot of people, but you don't need any of that to get a dual booting system going. - A lot of Linux installers will actually have an option right in the installer of the operating system labeled something like "Install Linux alongside macOS" or "Install alongside other operating system"
Career stuff is still a bit open ended - I do all the bookkeeping and admin for my wife's graphic design studio, so it would be used immediately in that.
Gotcha. Don't know what you're using now, but spreadsheet wise, LibreOffice is the most universally liked FOSS office suite.
But - it's probably dreaming because I'm in my early 50's, I might one day finish my Comptia A+ and get into a general IT helpdesk role. Then - if I have the energy (maybe once the kids move out of home?) - and general health allowing - I might study some cybersecurity. Or something with coding. Linux is kind of to save money and get another 3 years out of my iMac, kind of a hobby, kind of a 'career move' if I can ever figure out what I want to be when I grow up
, and kind of because the first 3 Seasons of Mr Robot were so cool. (He used Linux Mint and fired up Kali for attack runs. I mean, who wouldn't want to grow up to be Mr Robot when there are
adds for Kali like this one?
)
Oh no, I don't believe in "I'm too old for..." mentality. I'm sure you'll be able to do it! If you have the motivation I think you can do anything, really. Mid 50's isn't that bad either. Lots of great people have done lots of great things in their 50's and beyond. So cheers to good health and I'll be rooting for you
I'm happy to hear comp sci and cybersec is apparently considered cool, hehe. - If you in any of the learning endeavours - be it code or security topics or whatever - need help with anything, feel free to write me at any time. I never cared particularly for Mr. Robot, but at least it was a more accurate representation then the film Hackers...
As a Mac user, you'll also find that almost anything you learn on either macOS or Linux is applicable to the other system as well; At least when it comes to Terminal commands. Of course there are differences, but macOS and Linux are fairly similar in many ways and if a program exists on Linux you can almost always brew install it on macOS as well
Good luck with it all, and do let me know if you need assistance with anything - happy to help