I have one 20GB ext3 (Linux i.e. Debian Full install) partition, another 20GB BSD (Open BSD full install) partition, and the rest is free float that mostly I leave set to ext3 format as that is accessible both by Linux and by BSD. Generally I consider that to be a data partition, but do install other trial OS's/things into that periodically. 300GB physical/mechanical HDD has been way more than enough for my needs. I did have Windows installed as well at one time, but that has since been dropped (XP). I do however keep data on another removable HDD that acts as a file/data server. I also have a old PC acting as a HTTPS server etc.
Debian and OpenBSD were my preferred main choices as they're the top of the tree. Excepting Windows and the Slackware side of things pretty much everything else are derivatives. I've set Debian up to be bootable either as a full install, or as a Live boot type choice, were it all runs in memory/ram, but can be saved (or just have any changes lost) at shutdown. Not saving changes is handy at times for testing things out, perhaps messing the system up and a reboot without saving has you back to how things were before (OK). A single trusted/respected provider providing all your OS and programs is great as well. What with trusted programs and file permissions/security measures etc. along with running internet programs (browser) under a restricted (non root) userid ... you're pretty well positioned. Of the two Debian is better for desktop setups, whereas OpenBSD is good for server type use. I also run OpenBSD as a desktop system and it works very well for me (as my particular hardware sits well with OpenBSD). Personally I find systemD a bit awkward - different to convention and increasingly I'm moving more over to OpenBSD. My next setup could very well be just a sacrificial OpenBSD desktop setup (easily/quickly reset back to pristine again) along with a file server on another LAN segment, behind its own router (so isolated, but where files are accessible via reverse ssh). Having at least one other boot choice is handy at times if/when things in one system go wrong and where you can boot that alternative as a form of admin/repair boot. A simple CD/DVD or even USB/micro-SD boot can suffice for such purposes.
For ease of use however I often here that Mint or Ubuntu are preferred. I've not really used either myself, other than relatively briefly. Derivatives such as Ubuntu (based on Debian) can periodically introduce problems, for instance a little whilst back Ubuntu bricked some systems with a 'upgrade' (i.e. had to reflash BIOS or whatever, or for most - throw the PC/laptop away). Changes can introduce problems or security risks, so ease of use isn't a total freebie. Ubuntu is more like Debian Testing ... so less stable/greater risks involved, but more/latter software available.
Fundamentally Linux is just the core kernel. Debian however have build around that and provide/modify software to a level where the kernel and those programs work well together and are secure/patched. Expanding that 'kernel only' arrangement to be more like OpenBSD - that is a complete package (OS, gui desktop, httpd server ...etc.).
Overall however and I suspect Viper's suggestion might be your best choice. Relatively easy to get going and perhaps install/learn LibreOffice ...etc. and then take things from there. Linux does tend to tempt you to distro-hop and it can take years before you finally settle on a particular choice and have accumulated awareness of the syntax and differences. Maybe even start with a LiveCD/USB type choice that can run without making any changes to your existing setups.
Edited by rufwoof, 23 May 2018 - 01:12 PM.