Get some experience with a professional wedding Photographer,It will open your eyes to a realty that, what lens and cameras to take are not as important as dealing with people ,posing,understanding what the couples want,also taking charge at certain times of the wedding and reception if there is one.During the 80's worked as a wedding photographer and the guy that owned the studio toke my to about 3 or 5 weddings as his assistant be for letting me go on my own,and boy was I grateful for that! After I shot a few they became much easier and relaxed.Mostly used normal lens with a flash for fill or extra light.Hope I did not scare you ,but there is not much time to fumble with camera lens and try and think how to pose and arrange if you have no experience.
Mike