This answer is too late for the OP, but may be of use to future arrivals.
Ryanair cocked up my booking last year, which meant I arrived after 10.00pm, in Sevilla airport. I then took the airport bus into town, getting off early because I was at least a bit confused. (You should take it all the way to the bus station.)
A few years ago I was attacked and sexually molested at night in a city I knew well and loved; so was very anxious about walking alone at night to a strange hostel in a strange city.
HOWEVER - from the moment I got off the bus I could almost 'smell' how safe this city is. Fear departed and I walked all the way, using the map from hostelbookers as a guide.
When unsure if I'd walked past my turning, I asked 'Triana?' in a small bar and immediately a smiling guy jumped up to show me the way.
It was so very, very easy ...