First, congratulations!
I would say, as a former church wedding coordinator, keep it as simple as possible. For music, I favor traditional, like Ave Maria. There is a song called How Beautiful that is perfect for a wedding. Do you know which one I’m talking about? For the entrance, if you don’t do the traditional Here Comes the Bride, Pachelbel (I may have butchered the spelling) Canon in D is just right. Again, sticking with the traditional is easy and you won’t look back and think aaaah, what were we thinking. Ask the photographer to take a lot of candids at the reception. If you don’t have one, put disposable cameras at each table for the people to use to take pics. You may also ask a friend to go around with a video camera and have people tape their greetings or thoughts for the day. In the Church, make sure any photography is unintrusive and respectful of the surroundings.
As for the family, if you have a rehearsal dinner, that is a good chance for them to mingle. Can the parents tell some stories of you two growing up? Sometimes that helps people get to know you. I would expect the best of them and assume they will take the high road on this special occasion.
Good luck. If you have any specific questions about the ceremony, please ask.
Nicole