Making whole image/copy of my Win 10 & files

I see a lot of folk suggest http://www.easeus.com/backup-software/

I use other apps but here's a thing. It's not easy. It's easier than it was 20 years ago but you must apply yourself.

-> But if you want to try Ubuntu, why install it? It runs off a memory stick so no install is required.

you do not have to install ubuntu in order to try it. you can run it off a dvd, usb drive, or external drive.

however if you still want to create image of your drive. I would suggest using clonezilla. it is free and will create a drive image on your external drive.

Image your hard drive to an external it is easy I have done this so many times I have lost count.
Besides if you ever mess up your laptop you can reinstall everything the way it was at your last image. The last update of Windows 10 locked my computer for some reason and I was up and running again in 10 minutes. So if you want to install Ubuntu you can and no worry about not having Windows again at your command. You only need to create a usb boot disk with Reflect to put everything back in order again. There is a video of this on youtube to show you how.

If not, you should, regardless of whether try Ubuntu on your hard disk or some other medium as others have suggested. You you make your image copy is up to you, I see three very good options in earlier posts and there are several others but which ever you choose, do make one anyway and keep it up to date.

As for your Linux trial, given the choice of a USB stick or DVD live image, I'd use the USB stick, it's faster, especially if you have USB 3 ports and it's writeable.

Ubuntu is a popular choice, not my preference, I run OpenSuse Leap with a KDE desktop, also available as a live DVD and some would say Linux Mint is closer to the Windows look and feel. Since you don't have to install them, you can try one or two to see which you like best.

Depending on the particular laptop, many have easily changeable hard drives. You may want to consider getting another hard drive (perhaps a 120 GB SSD), putting it in place of your Windows 10 drive, and loading the Linux build of your choice. That way you can easily go back to Windows 10, if desired, or even switch to linux whenever you want.

Note: it is still a good idea to back up (image) your Windows 10 using Macrium Reflect, or similar utility.

Here's some advice, well, really more of a warning. Windows 10 already has a built-in tool for creating a full system image to an external drive, very simple to use. But here's the problem. It's very unreliable. I've used it to make full image backups, then done additional incremental backups, then suddenly, the old images get erased for no good reason. I've also had backups for multiple PCs on the same external drive, suddenly become inaccessible, all the files becoming locked so I can't even access them, again, for no good reason. So if you come across this tool, I suggest you don't use it, or at least, don't make it your only backup choice.