Shiva is a mantra. Who is Lord Shiva today? My Lord Shiva has a specialness that no other deity in the world has. He alone chooses His devotees. A lot can be said like this. Well, let's see the information about Shivratri 

Hinduism is not a religion, it is a code of life, a code of conduct for how a human being should live, the rules given by God to the people through sages, siddhas and sages. That is the real truth. Ok now let's see the individual answers.

Shivratri is not a festival! It is the Mahavrata which controls the mind. So, rather than celebrating this, it is correct to say that we are observing it

What is Shivratri? 

Shivratri is the worship of Shiva by keeping awake all night, forgetting hunger and sleep and thinking only of Shiva 

Once Vishnu and Brahma had a dispute as to who was the greatest and they appealed to Shiva to resolve it. 

He said that he is the greatest and immediately Vishnu turned into a pig and went to see his feet  Brahma He turned into a swan and went to see Shiva's head. Even though many ages passed, they could not see his foot or hair. Vishnu accepted his friendship but Brahma fell from Shiva's head He lied that he found Shiva's head with the help of Thalambhu and this angered Lord Shiva and Thalambhu was removed from Shiva Puja. And it is said that Shivaratri is the day when the arrogance of both is destroyed. 

History tells us that to worship him today our pride will perish  

This is the day when Kannappan fixed his eyes on Lord Shiva and achieved salvation. On Maha Shivratri, one should fast and observe the 4-day pujas at night and meditate on Lord Shiva. Next day evening at home, worship Lord Shiva by lighting a lamp and finish the fast. 

There is a Shivratri on every 13th / 14th night of the lunisolar month of the Hindu calendar, but once a year, before the arrival of summer, Maha Shivratri, meaning "the great night of Shiva", is marked. It is an auspicious festival that commemorates the "conquest of darkness and ignorance" in life and in the world

Shiv Pooja (worship of Lord Shiva) is done at home or in a temple. At midnight, Shiva Lingam Abhishekam takes place with offerings of water, curd, sugarcane juice, milk, honey, flowers and fruits to the Shiva Lingam.

Thus worship Shiva and get grace  ohm Namashivaya