With just one camera streaming direct from a smartphone may be easier.
Canon released software so you can use as a webcam with usb. Alternatively you need something like camlink to convert the hdmi out to usb. Either way it appears as a webcam input that your computer can stream…as long as it has an internet connection, either wired, hotspot or travel modem connected to a phone.
I’ve done both options from churches and they work well.
Sound is tricky, you may be lucky and able to connect to the church system especially if the have a loop system. Otherwise I place a mic close to one of the speakers and another for music and ambient sound.
To start I’d recommend keeping it simple with a smartphone and then build it up depending on what you need.