You need to get the Directors permission to bring treats. They may have allergies that prohibit what is served in this class and there are strict state child care regulations/guidelines about what foods can be brought by individuals. They have to be store bought for one, that way thay are not made in a non-health inspected home. Most schools are the same way now too. They have realized they don't know what kind of kitchens the home made stuff was made in and that they could be contaminated so they have pretty much stopped letting peoplle bring stuff.
The Directr or who ever answers the phone Monday morning can tell youif you can bring stuff and you can stop at the store on the way, or get a variety of stuff today and then pick from it after calling in the mornig.