In some places such as Major Cities like New York City the Mayor position is a full time job and pays pretty good.
But in smaller towns that have a lower population of under 1,000 people the mayor position is usually a part time job and some mayors of small towns may only make $200.00 per month to $1,000.00 per month at most.
It depends on how wealthy the city or town is.
Being a mayor you need a high school diploma and some places require more than that to qualify to run for mayor.
You are then voted in as mayor through a vote of people in the town.
Being a mayor is a good thing but it's also a lot of headache as well.