"WiFi has the self-assigned IP address and cannot connect to internet....

The DHCP server is malfunctioning or misconfigured or unreachable, so macOS uses a self-assigned IP address.

The renew button asks the local DHCP server to renew the address, which would get a response and an IP address vended from the DHCP server, if the particular problem here was transient.

It's also possible that this could be a problem with macOS, though the DHCP bugs that have been around are all very old macOS version (10.5-era), or with very old Wi-Fi hardware.

And if you have any anti-virus, anti-malware, app or cache or file cleaners, performance optimizers, any network-traffic monitoring and filtering tools, or other add-on kernel tools present, or any ad-blocking tools, please remove those per the vendors' instructions, reboot, and test again.

I'm familiar with organizations operating ancient and sketchy Wi-Fi devices and mixes of random stuff folks donated over the years, and others with well-configured and recent gear, and yet others with substantial and interconnected networks of access points for coverage across the facility. There've also been folks that have newly-encountered interference from internal and external sources, too. This is really close to a "how high is up?" question, without details of the config and the gear.

The DHCP server is a component of the church's network. This DHCP server is probably embedded within the Wi-Fi hardware, though it could exist elsewhere in the church network such as within the church gateway-firewall-router box. Again, details here vary by network. Sometimes widely.

I'd doubt that a DHCP renew request would change the outcome and would cause the DHCP server to vend an IP address here, but stranger things have happened.

If your Mac has anti-virus, anti-malware or network-monitoring add-ons or other similar packages installed, please remove that, reboot, and test. That stuff has had a very long history of causing issues and instabilities and oddities for various folks.

You could run/post an Etrecheck report to show what is running on your system. If any potentially adverse programs are running, the report should show that.

Please use copy and paste as screen shots can be hard to read. Click “Share Report” button in the toolbar, select “Copy Report” and then paste into a reply. This will show what is running on your computer. No personal information is shown. You can run the report for free at least once, but if you run it several times, at some point it will ask you to pay a license fee.

Etrecheck – System Information 10.10 and later

If you go to System Preferences/Network, select WiFi, Click Advanced, then TCP/IP, Renew DHCP Lease, does that help?