He asked whose past was he witnessing and was told his own
The first ghost to visit Scrooge was that of his business partner, Jacob Marley. Later Scrooge was visited by the Ghost of Christmas Past, Christmas Present and Christmas Yet to Come
The Ghost of Christmas past brings Scrooge to a party at Scrooge's first employer, Mr Fezziwig's.
At 1 am
Marley
The first ghost to appear before Ebenezer Scrooge in The Muppet Christmas Carol is the Ghost of Jacob Marley, Scrooge's former business partner. He warns Scrooge about the consequences of his selfish and greedy ways.
scrooge's partner Marley visited him first
The very first ghost is Jacob Marley
Technically, the first ghost to visit Scrooge was the Ghost of Marley (Jacob Marley, Scrooge's former business partner who died 7 Christmas Eve's earlier).
He takes Scrooge to his old boarding school.
The first ghost (having been foretold by Marley) was to take Scrooge back to his previous Christmases and allow Scrooge to see what it was like for him then and how this changed him
Scrooge was never a ghost in the story
The ghost takes Scrooge to the Corn Exchange - Here Scrooge would have been seen on a daily bases in his familiar place. On his visit with the ghost Scrooge hears business men speak of a sudden death and asking what will happen to the deceased properties. The ghost does not get involved in any discussion throughout his visitation to Scrooge