How can I change my iPhone homescreen wallpaper?

You can have a different wallpaper and Lock Screen. When you want to change your wallpaper just click on customize on the wallpaper and go from there. At least that’s how it shows on my iPhone 14 Pro Max iOS 16.1.

When I click on customize it lets me change the wallpaper. Not sure about the black lettering thing though

If you still have the wallpaper saved on your device you can use it. If you mean iOS wallpapers that no longer exist in iOS 16….you can search the internet to see if you can find the pictures to download and use. Note that live wallpapers may not be usable anymore in iOS 16 (not sure if this is for all devices that have it or just the 14 series). Otherwise please explain more clearly what you’re referring to.

Honestly never was a lot of tweaking that was available to begin with. Changing the picture you use. Maybe text showing a little differently based on background color. Live wallpapers (which some loved but really weren’t all that “live” since they wouldn’t move on their own so they weren’t really “live” at all. At any rate…changes happen after every major iOS update. Some people love. Some people hate. But never anything truly life changing (even with this update). Further changes may come. They may not. You can suggest things to Apple via feedback form.