I forgot my password for my Apple ID and don’t know how to go back in?

Read the article 'Two-factor authentication for Apple ID' (click here --> https://support.apple.com/HT204915 ) thoroughly. Various sections contain information that is key to you being able to set up and use a different telephone to get a verification code you can use. Failing that you can ask for account recovery.

"If your iPhone is your only trusted device and it is missing or damaged, you will be unable to receive verification codes required to access your account."

"If you can’t sign in, access a trusted device, reset your password, or receive verification codes, you can request account recovery to regain access to your account."

Read the sections about:

- Trusted phone numbers

- Manage your account > Keep your trusted numbers up to date and add a phone number.

- What if I can't access a trusted device or didn't receive a verification code?

And if necessary:

- If I can't sign in, how do I regain access to my account?

Sign into your account at https://appleid.apple.com/ and add your new number, then sign out of iCloud and back in again on your devices.

Get a verification code and sign in with two-factor authentication - https://support.apple.com/HT204974

Recover your Apple ID when you can’t reset your password - "If you use two-factor authentication and can’t sign in or reset your password, you can regain access after an account recovery waiting period." - https://support.apple.com/HT204921

See if you can get a Rescue or Notification email option. Link to contact Apple Support at the end of the 2nd article.

Apple ID - Manage            

Apple ID – Forgot Password