So was it Vespucci who 'discovered the north America?
...and did Columbus really travel that distance twice in 2 years?
Columbus' first trip was from 3 August 1492 to 15 March 1493. He departed on the second trip 24 September 1493.
Amerigo Vespucci explored the South American coast from Guyana southward. He never landed in North America, though the whole "new world" is named after him.
Bjarni Herjólfsson was a Norwegian who is the first known European sight the mainland of the Americas, in 986. But he didn't land since he was in a hurry to get to Greenland and had been blown off course. Lief Ericsson followed up on the report of land there and set off some years later landing as far south as possibly Labrador, Canada.
Juan Ponce de León, who arrived in Florida in 1513, is credited as being the first European to land in what is now the continental United States.