Questions on Kubuntu?

Having the LTS is good for a beginner, because it's very stable. That means that debugging is easier for you (you know that you caused the problem, not the software!). When you are used to Linux, and know what "normal behaviour" looks like, then you can move on to Latest.

I would not recommend Kubuntu for a beginner, because the K stands for KDE, the fanciest windows manager, which is very fine if you know exactly what you want out of the system - there's a huge temptation to add all sorts of bling and toys, just because KDE is so cool-looking. But a beginner can very easily tie themselves in knots.

I would recommend Linux Mint Cinnamon - really excellent user interface, looks like you are used to (but better looking!), and it's Ubuntu under the covers so it is still rock solid and easy to use. Everything in it seems to just work.

It doesn't make a diffference whether you get the newest or the LTS version. They've just announced the end of life for some LTSes we wern e expecting them to support a year or two longer. I've evolved into something of an Ubuntu-hater but part of it is Unity and their spinning off of Kubuntu to a community-supported distro. That doesn't matter so much and I'd say Kubuntu or Linux Mint are very good choices. But I'd probably get the latest version rather than LTS.

my advice if your new to this is dont dual boot it at all. Have it on a usb and boot from that. By the way Ubantu is more debian than Linux although appears similar to there desktop offerings from the past.