The Pope doesn’t actually earn income, but he manages the $300 million budget which goes to paying for all of the Pope’s expenses: food, travel, the Papal apartments, among other things.
A Pope usually stays Pope until his death. The most recent retiree would be Pope Benedict XVI who shocked the world with his resignation in 2013. He retired six centuries after Pope Gregory XII, who abdicated the Papal seat last 1415.
A Papal retiree will have a pension package. This infographic shows how his package compares to other top professions in the UK: