Linux noob here. Usually in Windows if I have a 1TB SSD, I make a 250GB partition for Windows and all of its things and I use the rest for a second partition where I install my stuff and store my files.
Usually in case Windows decides to go belly up, I still have my files. In more than 20 years it has never happened but I've always done it like that. I mean if Windows goes bad, I can still remove the drive and insert it into a different PC and copy my files away.
Should I shrink Partition 3 and make another one? Or keep it as it is? If I would, I read that I need to boot with a live usb to be able to shrink it. What kind of partition would I make?
Works well for distrohopping too, I usually would rename my home to oldhome or something and then just move my files to the new one to prevent dotfiles from potentially causing issues.
Also beware Debian installer with a luks encrypted drive. Where most things will unlock a previously-encrypted drive and use it, Debian installer will (or would, it’s been a while) reformat the encryption before it confirms any potential partition layout changes and you can end up with an empty drive before you know it.
Just add a new user when you install a new distro, then you can have a fresh start. If you want to try your old one, just
useraddyou old user and try it out.