Can someone explain what kind of attack U1 is?

Is it just a normal attack, a throw of some kind, I seriously don’t understand it at all.

I tried to counter with Yang’s U1 one time and I still got hit, so…???

it’s a normal attack. Though Yang’s Ultra 1 has little to invincibility to begin with.

I don’t know much about the game, but you can see some stuff about Yang’s moves at, for instance,

The row about his Ultra 1 says that he’s invincible for frames 1-9. So maybe you got hit on frame 10 or something.

Dash back then ultra?