my school organizes many workshops and one such workshop they had ganpati clay workshop in which children have to make clay ganpati and I had to help them. for practice I was told to make ganpati with clay. I hated it but had no other option. so in my mind I thought that I am just making an elephant and not ganpati. please tell me if I did anything wrong.

If it was an Elephant that was different story but they asked you make Ganpati is their Bhagwan which they worshiped. Speak with school authority and explain them in dignified way inshallah they will understand.