Is it proper to upgrade my iPhone 11 with iOS 16.5.1 or not?

Apple says: "Keeping your software up to date is one of the most important things you can do to maintain your Apple product's security."

There are different ways to ensure the highest iOS that your device will support is installed on your device.

An iPhone 8 or later will only update to the latest iOS, 16.5.1

This support article has instructions about updating an iPhone or iPad wirelessly --> Update your iPhone or iPad - Apple Support Read the article for recommended criteria for being able to use wireless updating.

You can also use Mac and PC computers to update system software --> Update iOS on iPhone - Apple Support

If you want a video about doing this, follow this link —> https://www.youtube.com/watch/1FcE86kwODQ

When updating, your device will update to the highest version currently available that it will support, or it will just say it is up to date (and can't go any higher) and won't install anything.