To recover a forgotten password, tap Forgot password? on the sign-in screen, then follow the message you receive. Do not create a new account: your data would stay in the old one.
On the sign-in screen, tap Forgot password?
Type the email address or phone number of the account.
Open the message you receive. You should see a link or a code.
Choose a new password, then write it down somewhere safe.
If you don’t see it: wait five minutes, then look in your junk mail. Still nothing? The account may have been created with another address: try that one.
Limitation: if you no longer have access to the account’s address, only the app’s help service can restore access. Its link is often under « Help » or « Contact ».
To picture it: a forgotten password is a lost key: you have a new key made, you do not change house.
Good to know: a real service never asks for your password by phone or by text.
Trusted links: Apple Account support · Recover your Google Account