Debian, I use one Gnome extension but could easily do without it. All the defaults are fine if you just want to sit down and browse, edit media, create documents or write code.
Easy mode: LMDE/Mint. They are all geared towards a good user experience and trying to keep you out of the terminal. I would recommend them to any new Linux user.
For a slightly more advanced experience, Debian with XFCE as the desktop. The installation is slightly less friendly and they expect you to be familiar with using the terminal and tinkering with the guts of your OS from time to time but you can have a ‘lighter’ installation with less background services. (I run Debian on all my machines so I have a bias towards Debian and LMDE).
Go to reddit, pick a username from the front page, use that. Any searching into your use of it will lead to that front page post and its reposts on click mills.
I’ve used VirtualBox for years and only just tried virt-manager. I wish I had tried years ago, so much simpler and it is in my distro’s default repository.
I used GNOME with no extensions for about 5 years. Recently I started using a window tiling extension but that’s only for for convenience, I wouldn’t say it’s fixing anything that is broken.
Ram is pretty much your limiting factor. I run the latest version of Debian on a machine from 2008 but it only has 1.8GB of ram so for a desktop it is a little sluggish.
So I found out that qbittorrent generates errors in a log whenever it tries to write to a disk that is full…
Everytime my disk was full I would clear out some old torrents, then all the pending log entries would write and the disk would be full again. The log was well over 50gb by the time I figured out that i’m an idiot. Hooray for having dedicated machines.