I want to erase all data on a new iPhone, new one already set up. I don't have a passcode for the old phone. How do I erase it? I thought I had but I get options to restore data which I don't want to do. Thx

Nothing. Once correctly erased, the prompt to again set up is correct.

That means there's nothing on it and must be set up to again be used. This leaves it ready for whoever gets it next to set it up from the beginning like you once did when you first bought it.

What were you expecting to see?

i hope this helps, if your able to get into the phone, you can go to settings, general, reset, and reset all data (tbh i dont remember exactly what setting it is, but you seem to know which one), but before, if you'd like, you can sign out of everything and delete your apps from the phone, sign out of icloud, maybe even delete the phone from icloud, etc, but just be careful with some things like notes because if those are deleted from that phone and they sync over icloud, it'll be deleted from every phone, also if you want you can hook it up to a computer and delete it from there (i believe you can by using a computer)

It does shut down, but then it automatically restarts, and shows the "Hello" screen.

If that did not happen then a step is missing,