Synology NAS. I really love that thing. I use their synology drive software to backup the Linux home folder, as well as windows PCs, iPads, iPhones etc. I use their photos mobile software to automatically backup phone photos and videos. I also synchronize a few select folders between PCs so certain in-use files are always up to date. I set the NAS to keep 30 old versions of every file. This works great for my college kids - dad has a copy of everything in case they nuke a paper or something (which has happened).
I stopped cloning drives long ago. Now I just reinstall the os and packages. With Linux, this is honestly faster than deploying a backup - a single pacman command installs everything I want. Then I just log into things as I open them. Ya I might have to futz around with some settings or redownload some big games on steam - but the eye candy and games can wait - I can be productive pretty quickly after an install.
I DO use btrfs with automatic snapshots (snapper and btrfs assistant). This saves me from myself when I bork an update (which I’ve done more than once). If I make a mistake, I just rollback a snapshot, and try again without my stupid mistakes. This has saved my install 3 or 4 times now.
Lastly, I sneaker net an external hard drive to my office. On it is a manual backup of the NAS. I do this once per month. This protects from catastrophic failures like my house burning down. I might lose a month or so of pictures in the worst case scenario, but I still have my 25+ years of pictures of my kids, wedding videos, etc.
In the end, the only thing that really matters is not losing my lifetime of family pictures and the good memories they provoke.
I’ve been a dual / triple / god knows how many OS booted since the 90’s.
Windows has gotten into bad habits lately - it’s not staying in its lane. Meaning it hasn’t respected other boot partitions for a long time, and recently there seems to be a lot of people having problems with windows nuking their linux installs.
My strong recommendation is to buy a second hard drive if you dual boot. Then windows can be “over there” - I’ve never had a problem dedicating ssds to the OS. My second recommendation is to do this now, why wait until you’re forced into something? You’ve got a year to learn Linux and get comfortable with it.