The Bonaventure is really nice!
DASH is a bus system. What you are going to do is get on the Metro Expo Line line, which is a light rail train, at the 7th/Metro stop, which is located 3 blocks away at 7th and Flower. The ride from that stop to exposition park is like 5 minutes, I believe it is the 3rd or 4th stop. It costs $1.50 each way. The shopw goes until 12am. They run the trains after 2am on Fridays and Saturdays, but they usually run them late on Sunday during FYF and other big events as well.
Also, i'll be trying to organize some meet-ups for lunch/brunch each day in the vicinity of the 7th/metro stop.