I need to change my password, I am locked out of my iPhone

If you mean the passcode, read the next section. If you mean password to your Apple ID, skip to the part at the end about finding lost information.

It appears you may have a disabled mobile device or forgotten device passcode. Refer to this support article for various methods that you can use to resolve this. Which one you can use depends upon your equipment configuration. --> If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support

This Apple article has instructions for what to do if you have forgotten your password --> If you forgot your Apple ID password - Apple Support

or go directly to this link --> http://iforgot.apple.com/

If you still need help:

Contact Apple for help with Apple ID account security "This article provides country-specific Apple Support contact information for customers seeking help with their Apple ID password or other security-related issues." --> Contact Apple for help with Apple ID account security - Apple Support

If you find you can’t sign in, reset your password, or receive verification codes, you can request account recovery ( How to use account recovery when you can’t reset your Apple ID password - Apple Support ) to regain access to your account. Account recovery might take a few days or longer, depending on the specific account information you can provide to verify your identity.