Many community event organizations share information to make each other's events better each year. There are registration days, Parent's Nights, picnics, all star games, parades, Opening Ceremonies, etc. Don't just ask about one event that a group might hold. This is a great thing to remember when dealing with schools. Do your best to have a pickup truck or float for your mascot to ride on.
Parades can be the worst events for mascots.
Not all parades start or end in the same place. Make sure the event host provides transportation for the character back to their car. If you have a local car dealer sponsor you may want to arrange for the mascot to ride in their car. Check this out with the parade manager, in case the car dealer is not a sponsor of the parade. Also parades don't often have changing areas for mascots.