Your audio equipment allows your guests to hear the wedding (via a microphone/input) and allows you to hear your guests (via a speaker/output). We highly recommend combining your input and output into one system by using an all-in-one Bluetooth device that provides both a speaker and a microphone—it’s magic, we swear. You’ll want to strategically place your magic speaker between you, your partner and the officiant (if on-site)
Another audio option that can work is an external USB microphone plugged into your computer as the input, with a Bluetooth speaker as the output. This does complicate the setup a bit more, so if you go this route make sure you have a good understanding of how audio works with Zoom.