If your package manager is apt, you can get a list of all the packages you have installed with

apt list --installed

There’s also a command to automatically reinstall all your apps from the list, I don’t remember offhand, but I usually just do them manually from Synaptic.

As other commenters have said, some people keep their /home on a different partition so you can reinstall or install a different distro without losing all your configurations (always back it up first anyway of course). But another thing I’ve done a lot is just have a different disk or partition with all my data files on it (called ‘data’ of course :p ), and I put a link to it in my home directory. So when I reinstall the OS I do have to backup my home dir and then copy it over to the new install home dir, but it’s small and just has my dotfiles and things.

Also on the data partition I have a backup subfolder where I keep a copy of any system config files that I’ve edited (usually found in /etc/), such as my pulseaudio config, so I can restore those.

And you can always try out different distros in a virtual machine or with a live USB before making the commitment of installing one on your hardware.

Ubuntu was my entry to linux as well, 19 years ago. But Ubuntu of today is not the Ubuntu of 15-19 years ago, and not in a good way.

When first coming from Windows, starting with Mint is the safest bet for a good transition because things will work pretty much as you expect them to, and there’s a very helpful forum if you have any questions. But I always say to try several distros and Desktop Environments to see how you like them. Everyone is different and it’s all a matter of preference.

I suggest that once you’ve got whatever distro you decided on up and running, install a virtual machine software such as Boxes (very simple) or Virtual Box (a little more complicated but with more options). Then just download various distros and make VMs for them to try them out easily. Have fun!

I’d rather have a linux OS on the phone that can run Android apps.