Try some good easy progressive dances to get folks mixing

is good advice. You may find from the first couple of dances that the particular crowd there are more comfortable with staying-with-your-partner dances, so be prepared to be flexible and change programme accordingly - and similar advice with the actual level of dances you do.

At a wedding do people are there to have a good time, not to complete an exam in applied ceilidh dancing; so if you end up doing very simple dances all night to a floor full of people job done, much more than if one set of die-hards get through something complex. Yes, it's dull for the band & caller, but that's the unbridled joy of wedding bookings :)

Lucky 7 , though, is a disaster waiting to happen - asking inexperienced dancers to count up to the dizzy heights of seven, whilst simultaneously doing a grand chain? Always ends in tears (for the caller, anyway, it's great spectator sport for the band) IMNSHO.

On a more positive note, Haste To The Wedding is a good tune & a simple dance.