First things on YT

First YouTube video was called "Me at the zoo"

First YouTube channel to Reach 10 million subscribers was Smosh. Smosh was the first YouTube channel to hit 10 million subscribers on May 25th 2013

First YouTube channel to hit 100 million subs was T series also on May,29th 2019. T series is a Indian music channel a bit like VEVO.

The first user to comment on YouTube was Marco Cassé from Italy, On a video called "Good Times!!!" He commented "LOL!!!!!!!" on June 14, 2005.