I recently made two mainstream videos which are a good introduction to CP, I think.

How to start with Competitive Programming? https://youtu.be/xAeiXy8-9Y8

About Programming Competitions (Codeforces, Code Jam, ...) https://youtu.be/cpguolx2oms

UPD

What is Competitive Programming? https://youtu.be/ueNT-w7Oluw (by tmwilliamlin168)

HoW tO BEcOmE rEd cOdeR? https://youtu.be/y7169jEvb-Y

UPD2

Steps and Mistakes https://youtu.be/bVKHRtafgPc (by tmwilliamlin168 again)