where did the state get its name from?
Purushottama Puri a place in the Rigved which was further shortened to Puri.
Puri
 In the Rigveda, in particular, it is mentioned as a place called Purushamandama-grama meaning the place where the Creator deity of the world – Supreme Divinity deified on an altar or mandapa was venerated near the coast and prayers offered with Vedic hymns. Over time the name got changed to Purushottama Puri and further shortened to Puri, 
what is puri? It is a city and a municipality in the state of Odisha in eastern India.
wiki:164074
Puri [SEP] Names in history
Puri, the holy land of Jagannatha, also known by the popular vernacular name Srikshetram, has many ancient names in the Hindu scriptures such as the Rigveda, Matsya purana, Brahma Purana, Narada Purana, Padma Purana, Skanda Purana, Kapila Purana and Niladrimahodaya. In the Rigveda, in particular, it is mentioned as a place called Purushamandama-grama meaning the place where the Creator deity of the world – Supreme Divinity deified on an altar or mandapa was venerated near the coast and prayers offered with Vedic hymns. Over time the name got changed to Purushottama Puri and further shortened to Puri, and the Purusha came to be known as Jagannatha.