Yaracuy is in Venezuela.
October 12 is the most important day where believers come from all over Venezuela arrive. It is worth staying overnight in the mountain (there's high security and many people sleeping on the grass). The rituals continue non-stop until the early morning and look especially dramatic at night. Best to arrive at Oct 11. At midnight on the main field, there is a stage where people would be hitting themselves with burning wood and walking on fire. It is best to ask before taking photos.
The state is rarely included on most tourists' travels around Venezuela.
From Caracas, there are direct buses (once in the morning around 7am) to San Felipe. At San Felipe, take another bus to Chivacoa. At the main plaza, there are buses that goes to the Sorte mountain. Alternatively, one can travel to Barquisimeto and take a bus or taxi to Chivacoa.