How do people celebrate it?

"During the festivities, the city is dressed in green and the streets are flooded in music and dancing. One of the most important attractions of San Patricio is the parade, that takes place in the streets of Dublin. In it, allegorical carriages and costumes are the protagonists".
 

The clothing is also a key point. If you're going to celebrate St. Patrick you can't stop wear Green clothing and use a clover in your lapel. Why? It is said that Maewyn Succat, popularly known as St. Patrick, who was a priest of Scottish origin, used to place a clover on his clothes as a metaphor to explain the mystery of the Holy Trinity. Then his parishioners adopted this custom and began to use the clubs during their religious services. Green, on the other hand represents spring and joy"

The main attraction of the St. Patrick's Day in Ireland is the St. Patrick's Day Parade.

• The St. Patrick Day parade is an import from the USA, where St. Patrick's Day parades have been held since 1947.
• Since the 1960s, Ireland too has known parades.
• From mid-morning on March 17th, across the country, the familiar drumbeats begin in towns in villages across the country, from Skibbereen to Sligo, from Clane to Kiltimagh.
• Somewhere between 50 and 100 parades are held before the day ends.
• The largest parade in the country is held in Dublin, where around half a million people line the streets.