I'm glad to inform you that to get the down town (Cathedral area) is better to take a bus (C1, 21 or 32).
The Metro in Seville has only 1 line, and is not much usefull to get the center, cause you have to walk 10min to get to the nearest station. We use the Metro to connect the suburbs with the town center in order to don't take the car to come to the city.
I hope this information will help you.
Get an answer from Ayre Hotel Sevilla staff and past guests.