I don’t think they include a Windows disk
“I don’t think they include a Windows disk”
Correct, most new computers come with a “one time one chance” opportunity to copy and make your own full OS backup mirror onto a USB stick. Some even require the stick to be a minimum of 32 gigs to even allow it because win 10 is 18 gigs alone.
But even though this is a very good idea to do right away first thing, it will be an exact copy of what is already installed in it. So if there is any garbage included you will be just getting it all right back again.
About the linux 18.3, stick with it and just upgrade the kernel only if you truly need to. 19.x is having issues they need some more time to iron out.