The goal of the Hour of Code is not to teach anybody to become an expert computer scientist in one hour. One hour is only enough to learn that computer science is fun and creative, that it is accessible at all ages, for all students, regardless of background.
Transit services. Union Station serves as a transportation hub for Portland. Portland's Greyhound bus station is the next building to the south, having moved to a new building there (from a location in the center of downtown) in 1985.
The Greyhound bus station is on Haines Street in Baltimore City. Kind of  near the Ravens stadium. It's 9 miles from the airport. There aren't any hotels near BWI that provide shuttles into the city as far as I'm aware. There is a Holiday Inn Express right next to the bus station.