Lord Ganesha, a famous deity in Hinduism, is younger son of Lord Shiva and Maa Parvati. He is also known as “Vighanharta” (the remover of obstacles). He is denoted by His elephant head, big belly, His mount and a small mouse. Ganesha's elephant head is the symbol of wisdom and His long ears signify that He hears everything that His devotees say. Although there are different mythological stories about why Lord Ganesha is worshiped first among other gods in every Hindu ritual.
What's the story behind his worshiping first:
Shiva Purana portrays a little story that connotes the custom of adoring master Ganesha first before all gods. When Karthikeya (Brother of ruler Ganesha) had a contention with Lord Ganesha about who is most savvies among the two? Listening to this, Parvati, mother of Ganesha, wanted to test them. She told them that as per the opposition, whoever circles the whole earth three times first are the most savvies between the two.
Kartikeya instantly sat on his vehicle and started his journey and went around the world on his peacock. When he came back, he saw Ganesha still standing with his parents. On the opposite side, Lord Ganesha circumnavigated his parents three times and proclaimed himself the champ of the opposition. Lord Shiva comprehended the shrewdness trap of ruler Ganesha yet sage Narada was still befuddled. Stunned by ruler Ganesha affirmation, Narada requested a clarification on how he turned into the victor? Ruler Ganesha answered “All living creatures of this universe know that my parents are the master of this universe. Additionally, for every child, their parents represent the world. Hence, by circling round the parents,I have circled the whole earth and since I did it before Karthikeya, I am the winner”.
Seeing this, Lord Shiva very impressed by Lord ganesha and declared that Ganesha is more knowledgeable, most savvies around the world. He gave him a boon that Ganesha be worshiped first before start of any religious ceremony.
The Scripture Ganapati Upanishat Says:
“Avirbhutancha sristyadau prakriteh purushaat param”
This means:
“Lord Ganesha appears even before the creation of prakriti(nature)and purusha(consciousness).”
Being one of the primary gods born in each materialistic creation, he actually becomes the first choice for worship. It is depicted in the Scriptures that Lord Ganesha is the ruler and remover of all obstructions.So he has another name “Vighneshwara(Lord of Obstacles)”, refers to his primary function in Hinduism as the master and remover of obstacles.