Hello Jenny. I actually been to Seville two weeks ago and it's great ! For sure they have a special accent but they are so friendly over there ! I've been amazed by how fast you make new contact abroad. So, don't hesitate and go on your own to learn as much and as fast as you can =)
Well, to be honest, the accent is quite confusive... They don't prononce "s", they speak really fast. You need a couple of days to get to used to it, but then all gesture helps you to understand what's going on. The city is really awesome, it's not big but it's worthwhile to go.