have new iphone. never set passcode. unable to get into phone

Which of the various locks?

The passcode lock can be reset.

If you forgot the passcode on your iPhone, or your iPhone is disabled - Apple Support

Activation Lock is a theft deterrent, and would not be much of a deterrent if it were easy to bypass. If this is Activation Lock, you’ll need the Apple ID and password holding the lock (remote release is possible via iCloud), or you’ll need the original purchase receipt and matching ID and a discussion directly with Apple.

Is this a new-to-you or new iPhone? If this is a new-to-you and not a new iPhone, contact the seller. Because if this is a new-to-you iPhone, you may have gotten scammed.

The All Too Common SAD Reality of Buying a used iPad/iPhone - Apple Community

What is the error message that you got? What is showing on the screen? See if this helps: https://support.apple.com/en-us/HT204306

Can we safely assume that this is a second hand phone, and is only new to you? New, fresh from the factory iPhones do not have any passcode set.