Before thinking about removing Windows 10 and loading Linux make a recovery flash drive to reload windows.
Then check someone else has been able to get Linux running on the same hardware as you have. Google search of model or main parts.
Most Linux variants can run from DVD or flash drive without installing so you can test before you install.
Generally Linux doesn't run faster than windows on the same hardware. Especially now when most hardware design is to run Windows 10. There are exceptions.
"Will it be difficult to use and understand Linux?" Not really, if you are happy with the software offered less difficult than some versions of windows. The internet has plenty of info and it is a great to have an OS which you can really get into and make your own. The only problem with Linux I think is there is to much choice. And what is current and the "best" this year will be surpassed next year or month. Buy some 32 gb Pen drives Apacer seem ok and are cheap . Disconnect, if you can your windows 10 drive. And try some versions have fun once you decide on a version then install it. Remember make the windows 10 recovery flash drive just in case.
Some to try
Opensuse tumbleweed,
Linux mint,
Ubuntu with the Cinnamon Desktop,
Robolinux, if you want to run windows programs the Linux is free but you pay for the Virtual machine software to run windows.
