For unlock your iPhone just setup your face ID or you can also use fingerprint to unlock is you are added. But now in today iPhone it is compulsory to add face id to protect data.
Unfortunately, if you forget your iPhone screen passcode, you'll have to sacrifice your data and settings in order to unlock it. One option is to enter the wrong passcode several times until you see the iPhone Unavailable message. Then, tap the Forgot Passcode? option in the bottom-right corner. Select iPhone Reset > Start iPhone Reset, and enter your Apple ID password to proceed.
If you have a computer available, you can also restore your iPhone using iTunes or Apple Devices on Windows, or Finder on a Mac. Of course, using a professional unlocking tool like Passixer iPhone Unlocker is another option worth considering.