I forgot my password to my Apple account

This Apple article has instructions for what to do if you have forgotten your Apple account 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 (read this support article: 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.

There's a difference between between a passCODE which is a four or six digit code used to unlock a mobile device after you turn it on, and a passWORD which is what is used to log into your Apple ID account. I am not clear as to which you are referring.

Read the Apple Support document for what to do if you forgot the passCODE on an iPhone or iPad. Click here then select your device type if necessary --> If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support - Which one you can use depends upon your equipment configuration.

Have you forgotten your Apple ID password? -> See this Apple article: If you forgot your Apple ID password

If you forgot your Apple ID password - Apple Support

Then see this Apple article: What to do after you change your Apple ID or password

What to do after you change your Apple ID or password - Apple Support

B T W:

You are sign in here .  .  .  with your Apple ID & Password.

Your Apple ID is the personal account you use with all Apple products and services. It includes the email address and password you use to sign in, as well as the contact, payment, and security details that you use with Apple.

You can’t merge multiple Apple ID accounts.

What happens when you use the same Apple ID & Password that you use to sign in here?

See the following Apple articles

Sign in with your Apple ID -> Sign in with your Apple ID - Apple Support

Manage and use your Apple ID -> Manage and use your Apple ID – Apple Support (UK)