The basic question of whether or not flying drones at weddings is legal aside, You can’t just fly a drone (UAV) anywhere you want to.
Apart from basic drone rules like not flying directly over crowds of people, aerial vehicles are banned at all major National Parks, and some cities don’t permit flying over private property.
Your church may or may not permit aerial drone video / photography, so if it’s something you really want, don’t leave it to the last minute to find out. Ditto with the wedding reception venue.
Some couples pick their wedding venues specifically with drone photography in mind, opting for venues with spectacular like wine vineyards and beaches etc. But just because a venue is “outside” doesn’t automatically make it fair game. As you can see from the photo, some areas that might look perfectly ok to fly a drone, actually prohibit all unmanned aerial vehicles.
In simple cases, obtaining permission is something that perhaps your UAV operator will probably check for you, but in all honesty, it’s better if you research this yourself to get what you really want and then have your photographer get the paperwork in place once you have a verbal “OK”.