Your hotel is near the city terminal at Jing'an Temple. You can go there and take the Airport Shuttle Bus 3 to Pudong Airport. It take about 1 hour to reach your destination. 3 hours is required for passengers to USA, other international destinations need no less than 2 hours before the flight. The airport shuttlt bus leaves every 15--25 minutes from 05:30--21:30, I think if you get to the city terminal at 12:00 you'll not miss your flight.