Hello, I understand how frustrating it is to not be able to connect to Wi-Fi. This article will provide some troubleshooting that may help. https://www.samsung.com/my/support/mobile-devices/how-to-troubleshoot-a-galaxy-phone-that-wont-conne...
If your phone needs to update, you may need to check with your service provider that they allow the updates over mobile data until you are able to connect to a Wi-Fi network. If you are unable to update either through mobile data or Wi-Fi, you may need to visit a local authorized service center to have the software flashed to the phone.
Service in the U.S.: http://www.samsung.com/us/support/service/location
Service outside of the U.S.:https://www.samsung.com/us/common/visitlocationsite.html
We also recommend submitting an error report in the Members app: https://www.samsung.com/ae/support/mobile-devices/raising-an-error-report-via-samsung-members-app/
Wi-Fi calling is a service provided by your carrier. For assistance with this feature, you will need to reach out to your service provider.