Linux OS for a new user

Hello users,

This question may be offtopic here, but i need your kind suggestions. I am now going to reinstall an operating system in my computer.
I had Windows 10 earlier. Now I am thinking to use Linux. I have not used it before so I have a few doubts.

Will it be difficult to use and understand Linux?
Will Linux be faster than Winodows 10?

Thanks

I am sorry but this is not a place for this kind of message.