Anyone who is in heaven is a saint, including the angels. Canonization is just the official process by the Church where this is publicly recognized and a Mass and Office are established for a particular person. However, this is rather recent:
St. Patrick died, and entered heaven, and has been celebrated as a saint long before the Church's process of canonization was even conceived.
Saint Patrick was a Christian missionary who brought Christianity to Ireland.
Saint Patrick was never a pope.
St. Patrick did not aspire to become a saint. He simply tried to do the will of God in the best way possible and that led to him being declared a saint.
No, he did not become blind.
St. Patrick was a Christian. Muslims are not Christian. As a result, they don't celebrate St. Patrick's Day.
Saint Patrick studied for six years to become a missionary.
No, Patrick's father was a deacon but his grandfather was a priest.
There is no historical evidence to suggest that Saint Patrick was a black man. Saint Patrick was a Romano-British Christian missionary and bishop who is recognized as the patron saint of Ireland.
(Magonus Sucatus or Maewyn Succat) was changed to Patricius (Patrick)
The official canonization process was not in place at the time that Patrick was declared a saint. No miracles were required.
how do you think he became a saint
They don't. St. Patrick's Day is a Christian celebration.