Well, elementary is actually just that... elementary (basic). It does not include LibreOffice like most other distros, but you can install it later. It is quite popular, from what I read, but I tend to encourage most new users to try Linux Mint. They say elementary is a bit more like a Mac, but Mint is a bit more like Windows. But neither one should be that difficult to use once you get it going.
Now.... that's the problem! You've got to get it going before you can do anything. Whatever is stopping elementary would also be stopping Mint. And this boils down to either Windows 10 affecting the boot process, or Lenovo itself. I have a Lenovo Yoga, and I have one of those special little buttons on the side too (called a Novo button).... and using it to boot the computer instead of the regular power button does work to give me BIOS and Boot options, and the Boot option will let me boot on a USB.
In my case, I have to hold in that Novo button for awhile (until I see the Lenovo logo).... and sometimes it doesn't work the first time and I have to try it again. I think this is probably where you need to concentrate.... to use that button (with the USB flash drive already plugged in.... and work with it to get it to boot on the USB.
There are some things about Windows 10 that may be a problem.... mostly, it is that it does not really shut down when you tell it to. Instead it goes into a "hibernate" mode so it will boot back up faster. This is a Microsoft trick to make you think it is so much faster than older Windows. But this is probably not stopping you from booting.
There are some things about the instructions you're following for elementary that I might do differently. But before going into that, let's just get you booting on the USB. When you do get it to boot... just choose to "Try Elementary" and not try to go forward with installing it yet.
You might also consider installing VirtualBox in your Windows 10, and then installing 2 or 3 (or more) different Linux distros as "virtual machines" to try them out before picking one to be the one that you install to the hard drive. This can be very helpful, and it also postpones the need to boot on your USB.