The package managers are actually a huge upgrade, at least in my opinion. I was always annoyed having to hunt for the right site for the right installer, now I can just search and install with a command without even opening a browser. But the biggest benefit is the updating. One command to update everything is so handy, one command and all my applications and drivers are updated just like that. But there is the issue of many programs simply not supporting Linux. For those you’ll sadly have to find replacements or workarounds.
If you want to get rid of Grub instead of what others have suggested, you could try booting into Windows and look for “advanced startup” and do a startup repair from there. That might destroy Grub and replace it with Windows bootloader again. If it works, your Linux stuff will remain on the drive, but Windows will boot like before. (you can easily reformat the HDD drive from Windows afterwards to use it for storage)
Some of my personal tips for moving to Linux:
It’s not Windows. Don’t expect things to work the same way. Trying to force Windows approach often leads to a lot of problems.
Watch Youtube videos about Linux. (terminal, package managers, desktop environments, distros, gaming, program replacements, whatever) This will help a ton to get a better grasp on why things work the way they do and what the benefits are.
Remember that in Linux you have a lot of options. Distro hopping can be useful early on to see different options/customizations. Then you can pick the things you like later.
Avoid graphical appstores. I’ve yet to have a positive experience with them. Terminal is much more reliable and simple.
Try out Arch Linux too, if you have the patience. It’s not as difficult as people often make it seem, and installing it yourself is very educational compared to the easier automated installers. AUR for installing programs might also be to your liking more than how Debian based distros do things.
Learn how to troubleshoot yourself. Learn to search the web for solutions. If you’re having an issue, it’s likely someone else has had the same issue before.