Greetings, and thanks for posting, PJJO!
It looks like you have some questions about restoring your iPhone. I’ve done this a few times myself, and would be happy to help!
Depending on your bandwidth, the software download can take some time. During this time, the download for your iOS software will continue in the background. Once the download completes, you can restart the process, and since the software is already downloaded, the process will complete.  If you receive an error while completing the process, If you can't back up your iOS or iPadOS device to a computer or restore it from a backup - Apple Support can help.
I hope that helps, and thanks for using Apple Support Communities. Best regards!