How to reset my phone password
Reset iPhone pass word
Go to Settings > Face ID & Password OR Touch ID & Password > Enter the current passcode > Choose Change Passcode
Now, if you have forgotten your passcode and you are locked out of your iPhone, you can't just reset it. You have to erase your iPhone using your home computer with iTunes by following the directions in this link --> If you forgot the passcode on your iPhone, or your iPhone is disabled - Apple Support
If you have been backing up your iPhone you can restore from backup after you get back in your phone. If you have not been backing up your iPhone all Data is lost.