Who is the oldest Super Saiyan?
The first Super Saiyan was Goku’s father Bardock. When Bardock fought Frieza, Frieza’s supernova attack somehow sent Bardock back in time thousands of years. Bardock was made stronger from the Zenkai of this near-death experience.
Is Yamoshi real?
Yamoshi in Dragon Ball Super In DBS Yamoshi was 100% confirmed to be real. Even though Super Saiyan existed, there was no evidence that there was actually a Super Saiyan before. But Shenron confirmed his existence and told the fighters how to channel his spirit to create Super Saiyan God.
Is bardock alive canon?
Well, the character Bardock is canon. However, Bardock the Father of Goku and the Bardock Special are NOT canonical. Neither were written/created by Akira Toriyama. However, the manga short, Dragon Ball Minus, which not only has Bardock but introduces Goku’s mother Gine, was written by Toriyama.