Why does my bike keep making this noise? Help

Might be the bb. Does your chain have slack in it or is it lubed?

Agree with the other on this one. Sounds like chain being way too tight. Drivetrain should spin pretty freely in a stand. Have a look on yt for how to tension a fixed gear chain. Lots of good videos on the topic

u want ur chain loose enough to where u can move the cranks back and forth