Hi Mike,
I'm only on here briefly these days (every few years) when the forum pops out a 'see what you've missed' email. So, while i was reading the email, I saw your post in the list, and having been active in new member support on various Linux forums over the last 20 years I thought I might toss this into the grab bag.
Sorry it is a long read, but I might not get back much, so I'll make it as informative as possible.
Linux Mint no longer supports, nor has a desktop environment (the 'windows looking part of Linux) based on KDE/Plasma (that's what Kubunutui runs).
It does however have its own very popular default desktop called Cinnamon, and another called MATE.
It also supports and offers a desktop environment called Xfce, which is quite popular on lower spec systems like your Acer. I am running all sorts of pretty intense things on my Mint Xfce system.
So 'if' you decide to install Mint:
Regarding the 'Desktop Environment'
First thing to do is try to watch some YouTube videos about 'Mint Cinnamon', 'Mint MATE', Mint Xfce'
See which one you like most and that you personally would like to be looking at, working with etc. on a day to day basis, and choose that one to burn to your USB stick. It is a P A I N to try to install a different Desktop Environment later
While you are considering though, remember, like ALL Linux Distributions, 'how it looks' is very, very configurable. For example, I even have transparent File Manager Windows (completely useless) and video wallpaper (also completely useless). You will never need to do that stuff - but some of us just do it because we can.
SO basically, pick between Cinnamon, Xfce and MATE based on what YOU would like to see/use every day.
You might find inspiration here:
Mint Desktops Compared
Mint has a very very active forum, just like Linux.org, and their members are likewise, always ready to help.
Regarding the RAM
I have 8GB RAM and 1TB Hard Drive. My desktop has a display on it that says I am using 1.95GB out of my 7.65GB available RAM. I have something called 'swap' set up as a file on my hard drive in case I ever run out of RAM - but I have never, ever broken the 4GB mark yet. So you should be fine with a 4GB RAM system.
Regarding the Hard Disk.
When you are installing Mint, you should never do the 'default' install. Do a manual Install. I think the option is still called 'Something Else' it will be something that sounds like that anyway.
Once you get there you have to configure partitions on your Hard Drive.
A few things to remember (these are ESSENTIAL!).
The root partition / should be 50GB (it will probably show as 46GB on your system later, but that's a system thing. Make it 50GB when you are choosing and that will be fine. Your programs are usually installed into root, so this grows a lot. Mine, with a lot of heavy duty stuff installed is still only using 25GB - but making it bigger once it is installed is a real pain (if you run out of space).
DON'T set up a 'Swap' partition.
Mint uses a swap file by default and it only appears if you run out of RAM, then if goes away. That's why you can get away with 4GB RAM. You will probably never run our - but just in case, the swap file will be there.
That's about it. Unlike Windows - you never have to Defrag your drive. In fact it is a good thing to remember, because from time to time someone will offer a Defrag program / App for Linux. Just 'DON'T'
Some other members here are likely to comment on this advice. If they agree or disagree - read their suggestions too. We all have slightly different experiences and it is worth comparing different views.
ALSO - I am talking about Mint because you mentioned it. There ARE other options that are just as good as Mint. REMEMBER ( I'm shouting - for emphasis - sorry) to look for YouTube videos on whatever options you are considering.
Most of all - Have Fun and enjoy the Linux Community AND especially Linux.Org Forum.
Cheers, RossD
Just for laughs, here's an example of some of the completely unnecessary KDEish theme stuff you can do with Mint Xfce if you are crazy enough.., including my home made 'Minty Green' theming, and a desktop indicator called a 'conky' that can be written for any Desktop Environment, not just KDE or Xfce that shows my RAM usage, CPU load, VPN situation and the time/date at a glance.
You can make Linux look like whatever you want really!
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