The Shinto priest is easily misdescribed by analogy with clergy who teach and preach, because the office has very little doctrine to teach and is built around something else entirely.
Purification and offering
A kannushi serves a shrine and the kami enshrined there, and the core of the office is purification and offering: the priest purifies himself, the space and the participants, presents food, sake and other offerings, and recites norito, formal addresses in an archaic register of Japanese. What is being managed is ritual purity, and the ordinary business of the shrine, the purification of a new building site, a car, a business, or a newborn presented at the shrine, follows from that rather than from any doctrine the priest expounds. Shinto has very little doctrine to teach, and the office reflects it.
Certification and who serves
Priests are certified by the Association of Shinto Shrines through its universities, Kokugakuin in Tokyo and Kogakkan in Ise, in ranked grades. Marriage is normal and many shrines pass within families, though the hereditary system was formally abolished when shrines were brought under state administration in the Meiji period. Women serve as kannushi, and their numbers grew substantially after the Second World War when many priests had been killed, though they remain a minority of the total.