The one piece of advice I'd give you is that if you're going to be shooting a wedding and especially if you haven't done one before, you practice and know for sure the things that will work.
When we got married many years ago, we relied on a bunch of friends, including some that were supposedly sophisticated shooters, to cover the wedding. We had like 6 or 7 of them, and guess what? NONE of their stuff was any good. This was in the old days of film and 35mm, but most of the pics were underexposed, overexposed or blurred. The only good pictures we have of our wedding are the "formals" that were taken by a professional that we hired, and to today, my wife is still ticked off about it. The thing with a wedding is that.... you don't get a 2nd chance to do a re-shoot
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