want to try Linux, probably Ubuntu or Mint.
Both of those are great choices for a beginner (or expert)
. They are also both distributed in a live form, which means you can try the OS from the installation medium, before you install it. Keep in mind that it will typically run slower in try-mode than when actually installed because DVDs/CDs/flashdrives tend to have slow read-speeds/write-speeds/access-times.
Do all the Linux releases use the same line commands?
A commandline is a combination of a shell (application used to execute commands)
, and any applications you execute from it. Most distros use Bash as their shell, but it's by no means the only shell available. Different shells have different features, but the command used to execute a given program is the same, because it is determined by the program not the shell. The applications installed will vary from distro to distro. If an application isn't installed you can install it, though the ease of this proceedure will depend on the distro being used. Both Linux Mint and Ubuntu make
it easy to install a large number of applications you're likely to want.
am wondering things like (with either Ubuntu or Mint) how often I'll have to use command line to get things done?
Depends on your usage. You should expect to use the commandline atleast a bit, as it's quite common to use it when troubleshooting. While many people don't take this advice, I would suggest you never run any command you don't understand. Look it up, or ask. This applies even when a command is suggested by someone you trust, because they could have made an unnoticed typo, or the command could require adaption to your usage senario (and they may have assumed you'd know this).
Can I copy files, move things around, delete files, etc. in either of this distros without going to command line?
Yes. Both Linux Mint and Ubuntu come with a file-manager application. On Windows the file-manager application is "explorer.exe". On Ubuntu it's Nautilus, on Linux Mint it's Caja or Nemo (depending on Linux Mint flavor). You can install others! Additionally both of these distros come with tweaked settings to make it easy to mount drive partitions from the file-manager by clicking on them.
I see different people talking about Virtual Machine and running Linux in there. Is that an advantage?
If you have a computer powerful enough to run a virtual machine, they can be very useful for testing Linux distros, because if you botch something while fiddling around, you haven't damaged your main OS. They are also a great option for people who have never tried Linux, and wish to get to know it without installing it on their computer, because they don't know if they'll want to keep it.
Is there an advantage to dual booting
Sure. Dual-booting, triple-booting, multi-booting, etc, allows you to have multiple operating systems rather than committing to one. This can be a great option for people whom have Windows, but are starting to learn Linux, because they can take a break from Linux if they need, which is useful if they need to do something, but haven't yet figured out how accomplish it under Linux. I usually advise newcomers to dual-boot rather than outright ditch Windows, especially if they've never actually tried Linux before, just in case they hate it. What OS to use, is a big decision.