Ubuntu

I feel like the cool features I think of are generally Linux features

• You can periodically have scripts run by setting up from jobs(e.g. make a temp folder that deleted it's contents every 24hours or update the programs on your computer at midnight everyday)
• Ricing your desktop, I've never done it but there's an insane amount of customization you can put into how your computer looks. Just look at unixporn(it's just nerds showing off their desktops) to get an idea
• Getting used to using your package manager, it's extremely nice to not have to open up a browser to download software but to have one place to look every time you want to find software (try using the apt search command)

Picking Ubuntu was a really good choice for testing out how it'd feel to use a Linux distro. That isnt to say there aren't things that the average user wouldn't like when using it. If you need to use office software, there is Libre office suite, but it's just not as widely used or feature full as the Microsoft suite. Or if you're trying to sync files across devices, I swear every linux user has a different means of doing so (one place to start would be Syncthing).

I hope you have a great experience and that you learn a lot from it.