Hi, I'm one of the three techies at my place of Worship. We have state of the art audio everything for our modest sized (150) person place. One of my duties is spectrum management, and I actually frequently bring in a Siglent SSA-3021 to deconflict the wireless microphones from the nearby TV stations and the cell site in the back yard. Because of Covid and an elderly congregation, recently we have had to get into streaming video in a serious way. We started with IPAD/IPOD video over WIFI and dedicated hotspot, thinking it would be easy and that we had plenty of bandwidth. Worked in an emergency, but we are moving off it as rapidly as possible to a dedicated hardwired system.
So here goes:
One. Blessings to you and your Bride on your special day..
Two, Weddings are HER special day. You do not want to annoy her and your mother-in-law/future babysitter by futzing about with Mystery hardware on HER special day. Since she was about six years old, she has been dreaming of this going perfectly. Instead spend time learning to Dance, writing a speech, and making sure your best man is not a clueless person with no planning. All your focus should be on her. This is how it should be. Delegate stuff to mature individuals who have a clue.
Enough said.

Three: You touched the existing hardware as a professional, so if you stay there, so guess who is the new facilities engineer. Not listed in the Holy Books, but YOU are the new in-house techie by virtue of Marriage.

Four:
Despite having a really good WIFI setup with a business class Cable TV internet feed, care to guess what happens on both WIFI bands when 75 ladies and quite a few gentlemen turn on their phone with Bluetooth and WIFI? Also care to guess what happens to one sector of the local cell site? It is literally in the back yard there, is massive, yet gets overwhelmed. So it starts throttling.
THUS
Hardwire everything..... Even though we have dedicated WIFI nodes for audio and video, every phone in the place still pings them, or causes interference, causing dropped packets. DO NOT GO WIRELESS. Even a prosumer grade camcorder on a tripod beats the phone, except in resolution. Most newer camcorders can stream for you.
Five: Have backups, two cameras, two audio feeds. We are amazed how often a musician or guest, or even just an excited congregant can cause a new issue, and the three of us have been doing this for years.
Six: It is OK to stream, just don't count on it for anything permanent. Streaming seams simple, but you have very little, if any, controls over the automatic allocation of bandwidth in the downstream path. Trust me on that, lost packets was a major topic of our post service critique today. When we rehearse, things are empty. When we have an actual full up load, things are VERY different. Streaming services can do strange compression things when many people start viewing your stream. So stream everything to a dedicated local hard drive in the building. Edit/Example We had a measured 3 minute Facebook Video latency today.
Seven, No plan of battle survives first contact with reality. Hire a professional with a track record. You don't want to be futzing hardware during the rehearsal dinner anyways. Have checklists.
Eight: Reach out to others, another place of worship in town will often be able to loan you a techie, costs you nothing more then another plate at dinner. We get calls fairly often when another techie is out of town or ill. We go. It's odd doing a stranger's funeral or wedding, using some one else's setup, but rehearsal cures a lot of ills.
Nine: Digital Processing Delays happen. Not fun when the audio does not match the video, its very annoying and visible.
Ten, Don't forget the lighting. LED DMX rental fixtures add punch to wall up-lighting etc.
EDIT, I checked with the software end of the team, HD streaming for one video at a time costs us a minimum of Three Megabits per second, and that is lossy with bad dropouts on the 2.4 Ghz WIFI we started with. I moved the team to 5.6 Ghz WIFI nodes last week to get that extra Bandwidth, now we have less problems but four active cameras pushes the limit on the WIFI. We select one IPOD/IPAD camera to stream using software at this time, but all four are always active senders. This is why I spent my evening learning about PZT cameras , SDI / HD signaling, VISCA, and video mixer consoles.
Steve