The nvidia driver comes under the non-free one.
The nvidia 510 driver would be the most suited one for you.
The latest might be for the 4080 or the 4090.
Here is the link.
If I am correct mate doesn't have many touch gestures so there is no effect for it. If you want gestures gnome or kde would be suited. I maybe wrong if so any seniors do correct me 😉
In the GitHub it is written that you should only use fusuma.
About that error, in windows, you have two users say administrator and user. Both the users have their own user folder,they can't tamper with the others users folders right.
Similarly linux in default install has two users one the root and other the user. When you use sudo you are asking the root to open the file in its folder not in yours.
For the nvidia card it may be terrible. I have one it would always black screen after every update.KDE is pretty much halted for now since they are getting ready for plasma 6. There are not much resources for KDE neon compared to other main ones.
Well you can use the web version.