I’ve been to dozens of weddings over the years and it always amazes me when a groom or bride doesn't know what to do during the ceremony.
I’ve seen grooms come down the aisle and not know where to stand. I’ve seen brides not sure what to do when they get to the end of the aisle—await the groom to get her or walk alone to the altar. And in Jewish ceremonies where the bride is going to walk around the groom seven times I’ve seen grooms actually try to follow her in a circle because he didn’t know what to do. (He just stands still.)
This is why it’s important to have a rehearsal either the day before the wedding day (and before the rehearsal dinner) or before the guests arrive on the big day. Your officiant should go over with both of you what will happen during the ceremony including, what he or she will say, the order of the ceremony—blessings, drinking wine, readings—where everyone stands, etc…
Your wedding is not a dress rehearsal. It’s the live show and you don’t get a do over once the music is cued. A rehearsal should not cost you any money and it will truly help you understand what to expect so you’re not caught off guard or embarrassed in front of your guests.
And don't be embarrassed to ask for a rehearsal with your officiant either. He or she shouldn't have any problems going over the service with you. If they do, that's a problem.