[Sime]

I'd pop the little fella mostly on Auto if you have just bought it. There are lots of settings [portrait being one] that you could have a go at.. Get the camera out and take lots of photos of the people around you before the "big day" get familiar with it and practice. You want to know where all the buttons are on the day. Take shots with as high a quality as the card will afford you on the day. Good luck...