unixbird

Yes its the same, they may have different packages though (actually they do). So some package commands will be different ie you wont have nmap unless you install it.

I would go VM just to get it all comfy for you and get you familiarized with everything. Afterwards i would do straight dual boot, and recommend you use a different storage device for linux (grub will overwrite windows boot stuff which isnt a problem, but windows likes to just kill grub whenever it pleases so linux can stop booting without reinstalling grub). Apt is a great starting point, RPM based package managers are a big PITA if you havent used linux deeply before

naw you wont be missing much, opensuse uses RPM like fedora does, but I never had good luck with opensuse. Mint isn't that secure (theres lots of reasons why you could google them), and elementary is okay. Ubuntu is a really good all around distro to be using as a beginner