i forgot my iphone password

If you forgot your iPhone Lock Screen passcode:

If you forgot a passcode that you changed within the last 72 hours, see the following for instructions: Temporarily use your old passcode when you forget your new passcode on iPhone or iPad - Apple Support

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

or if you forgot your Apple ID/iCloud password:

There is an Apple article that explains what to do if you have forgotten your Apple password. Click on the following link: If you forgot your Apple ID password - Apple Support