I recall an interview with a young Austrian by the name of Florian Wiltschko who'd become a Shinto priest in Japan.
Here's an article on him:
Blue-eyed Austrian finds calling at shrine | The Japan Times
I am certain that he could help you find more information on how to become a priest, as well as on how to set up a Shinto shrine or at least connect you to other sources. I couldn't find his contact details, however, John, the webmaster of Green Shinto, can put you in touch with him:
Florian Wiltschko | Green Shinto
It appears Florian was ordained at Nobeno Shrine in Tsu City, Mie Prefecture, in 2016.