need passcode to open iphone

I think it’s extremely unlikely that you never entered a passcode. When you set up a phone it forces you to create a passcode. However, if the phone is asking for a 4 or 6 digit passcode and you don’t know it there’s only one option. See this Apple support link→If you forgot the passcode on your iPhone, or your iPhone is disabled - Apple Support

Or watch this companion video ⬇️

Hello ~ Are you the original owner? Did you purchase the iPhone second hand? Take a look here paying particular attention to *Check for Activation Lock before you buy a device from someone else* section:

Activation Lock for iPhone, iPad, and iPod touch - Apple Support

~Katana-San~