St. Paul will kick off the summer party season this Sunday with the annual Grand Old Day. The street festival is the largest one-day festival in the upper midwest and includes a parade, a race, multiple concert stages and all the food booths one could wish for. The event started 25 years ago when some Grand Avenue merchants came up with the idea of hosting a party to bring more people to their stores. Billie Young was a shopkeeper at the time. She's since sold the store and written a book about the street called "Grand Avenue: The Renaissance of an Urban Street." Young says the event had a modest beginning: Billie Young is the author of "Grand Avenue: The Renaissance of an