I fully switched to Linux many years ago without any regrets. It was the time when Win7 was in development. I was using win XP and had try ubuntu a bit, and I promised to myself never again to use windows personally. It really worked well so far. You are so welcome to your journey on using Linux, you'll be more sovereign and more free, having more control over your OS. Please start with Kubuntu LTS, the interface is similar to windows because M$ copied the KDE theme a lot, and Kubuntu is stable. This is the distro I installed for my parents and sisters and recommand to beginners.

For Office alternative, of course you have LibreOffice, but if you want a more similar Office experience, try out WPS (I know it's chinese, but what can you do).

Don't worry, you're not late to switch to linux, because after 20 years, it has become only better. After a good year of using your kubuntu, you'll feel more confident, and you can experience other distro if you like to change. KDE and Gnome are both working on an immutable OS like NixOS. So wait and see, it will only become better.