Leaving from GrandePortoHotel on Rua Sta. Caterina on May 4, going to a hotel at Fontana Park in Sandanha District, Lisbon. Need guidance on closest train station in Porto and station nearest Fontana Park where I can take a taxi to the hotel. I see there are many choices for train service. Prefer fastest service for arrival in Lisbon by 1pm. Must I buy ticket ahead of time, and where?