I forgot my passcode to unlock my iPhone

There is an Apple article that explains what to do if you have forgotten an iPhone or iPad passcode. Click on the following link: If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support

If that option is not available, you will need to use a computer. See: If you forgot your iPhone passcode - Apple Support

Follow the instructions in the Apple Support document above your name to reset the iPhone and then set it up again.